Cheating Girlfriend's Sister

Penny Duran has a lot of things going for her. The leggy 18 years old brunette is a beautiful girl who is also very tall at six feet two. Her face is absolutely perfect, even when she isn't wearing make up. Her body is even better, being both curvy and toned from countless hours in the swimming pool. She is, after all, the captain and ace of her high school's swim team. Penny has set the school's record for women's 100m butterfly at a very impressive time of 59.21 seconds, one that is two seconds faster than what the previous record was. She could recall being so jubilant when her coach called the time and the full impact of what she accomplished dawned on her. The brunette also set the school's female 100m sprint record at 12.96 seconds.

Despite already being an awesome girl with lots to be proud of, Penny is still fixated on two things. One of them is her future career. Her mom Heather is a veteran, a Navy Captain who was stationed on an aircraft carrier in the Middle East. She wants to follow her footsteps and join the Naval Academy when she graduates from high school. Like her mother, Penny is in excellent physical shape and also performed very well academically. This goal shouldn't be too difficult for her to achieve, if she doesn't screw up anything too badly this year. It should be easy enough for someone whose physical fitness is in the league of Olympians. Her best time is only four seconds slower than the world record.

The other problem she is facing right now is much more difficult. The strong brunette is secretly in love with her big sister Kath's boyfriend Tim. She has been in love with the adorable 20 years old guy ever since they met 11 years ago. Yes, he is a dork, but he's a very sweet and cute one. The kind college sophomore is now home and she wants to spend time with him. Her sister, who got their mother's blonde hair while Penny inherited their dad's brunette hair, only got Tim since she reached the dating age first and was able to ask him out before Penny could.

She isn't sure yet what she is going to do about her situation. Her sister may have the larger boobs, but Penny's ass is better. It is round and very muscular. Kath's ass is really good too, but it is mostly fat and doesn't have as much muscles. Her thighs are also way more muscular than Kath's, thanks to all the time she spends swimming with her friends on the team. But Tim isn't a shallow boy who would just cheat on his girlfriend, despite how much she knows muscular legs turn him on. She's been through his search history when he allowed her to borrow his computer and found a few really interesting bookmarks.

It makes her think about raping him, but that just seems so wrong. He is her sister's boyfriend. She couldn't just go and rape her sister's boyfriend, right? If he isn't dating Kath, then she wouldn't hesitate. She would rape Tim until he is addicted to her pussy, had it not been for Kath being his girlfriend. Her sister is really the only reason Penny hasn't raped him already. Right now she is busy thinking of if she could make the two of them break up. It would be the most awful thing she'll ever do but she can't see any other way to get what she wants.

Meanwhile

Kath is visiting her boyfriend's house. She and her little sister Penny grew up with Tim. The young military brat has been in love with him since they were children. Even though Kath isn't as fit as Penny, she is still in extremely good shape. Penny just has the body of an Olympian and athletic abilities that could one day allow her to become one. Kath knocks on the door and waits for Tim to come and open the door for her. She's surprised when his dad John is the one to open it instead. "I took a day off today," he explains as he lets her in. "Tim is out at the bookstore with a few of his friends."

John eyes his son's girlfriend's ass with a peering expression on his face. She has a very thick, healthy derrière that he can't help but stare at every time she comes over. It is just giant globes of fat. Kath could feel his eyes on her butt and blushes. "Thank you for letting me stay and wait here," she mutters, pulling down the hem of her skirt. She tries to adjust the denim skirt so it wouldn't catch his attention as much but the tactic doesn't seem to be working. He is still looking at Kath's booty when she turns around and sit down on a couch, getting her Vogue magazine out to start reading through it.

Even though this is his son's girlfriend, John couldn't help himself. The man's inability to keep it in his pants is the reason he and his wife got a divorce. John wanted to go live with her but she died in a car crash before the court can decide on who gets custody of him, so he had no choice but to live with his cheating dad. "Is my son taking care of your needs?" John asks Kath, who just glances at him quizzically. "I should have been more specific. Is he good in the bedroom? Does he fuck your brains out the way a beautiful young woman deserves to be fucked, Kath?"

Kath blushes at the handsome older man's blunt words. "I don't think that I should be talking about that with my boyfriend's dad," she says, trying to get up from the couch and leave. But then he drops his pants and her jaw drops in shock. Tim's cock is only four inches and Kath has always had to rely on his tongue to get off. But his dad has a much larger dick. It is seven inches when flaccid and after he strokes it to get an erection, the cock is now eleven inches. "Oh my god!" she squeals out in shock as the monster cock juts out at her, looking ready to fuck.

John smirks proudly at her reaction to the sight of his penis. He beckons her forward and she leans in, moving closer to him. "Go ahead," he says. "You can touch it if you want." Kath tries to stop herself but ends up touching it, gasping as she feels how incredibly hard his rod is. "Do you like it?" She nods. "Good. I want you to be honest with me." Kath is now subconsciously caressing it, using both hands since it is so long. Kath's hands couldn't even wrap around the entire girth. It is as thick as his wrist. "Whose cock is bigger? Me or my son?"

Kath is suddenly jolted right out of her reverie and realizes what is going on. But then John slaps his cock across her cheek and smears her face with his hot pre cum. This dazes her and she ends up admitting "Your cock is so much bigger than your son's," she says to him and continues to stroke his dick. Kath is now jerking him off and kissing the tip of his penis. "It is so much longer and much thicker too." Her mind is now turned to mush with lust for the massive pole. She couldn't believe how large the shaft is. It is incredibly huge!

"Suck it," John orders her gruffly. "If you want me to fuck you with it, then give me a blowjob, slut." Tim has never spoken to her like that. A part of Kath has always secretly wanted to be taken roughly and dominated. Since her loser of a boyfriend couldn't give it to her, she will take it from his dad. The sexy blonde sucks the tip into her mouth and slides her lips to the middle of his shaft before starting to gag. After a few minutes, she manages to adjust and ends up deep throating him. She could do this since she has deep throated her dildo before when she was really horny.

The blonde boba her head back and forth as she spears her own throat with the massive prick. He thrusts into her tight throat and uses her, face fucking his son's girlfriend hard. "Do you want your boyfriend to see this? How do you think my son would feel when he sees you sucking my cock and letting me cum down your throat?" Hearing him say that lights Kath's pussy on fire and she rubs herself through her skirt as her boyfriend's dad face fucks her until he finally starts cumming in her throat like he said he is going to.

After pouring some semen down her throat, John yanks his dick out and then sprays the rest of his load onto her beautiful face. He grunts as he blasts his son's girlfriend's face with ropes after ropes his warm cum. The man couldn't believe he is actually doing this, spewing strands of his jizz on the blonde's perfectly made up face. John keeps on ejaculating onto Kath's pretty face, decorating her with his thick and creamy semen. Soon, he has glazed her and soaked her cheeks in his warm cum. Kath gives him a shy smile with her face painted by his semen, totally drenched.

John hasn't had enough yet though. He grabs her by her curvy hips and yanks her skirt down, revealing that she isn't wearing panties. "I came here to seduce your son," she whispers. "But he is such a limp dick loser, I'd rather let his dad fuck me instead." The much older man doesn't need to hear another word. He tosses her onto the couch and then gets on top of her. Then he lines the tip of his cock up with her entrance, poking inside the warm tunnel. With some difficulty, John manages to penetrate her, making her cry from pleasure as he stretches her out.

He starts fucking his son's girlfriend really hard, slamming in and out of her with his huge rod. It throbs inside the blonde, who screams out in incredible pleasure. She has never gotten fucked this hard before. It feels so amazing and the illicit nature of the lay only turns her on more. "Do you like how I fuck you? Do you like getting fucked by your boyfriend's dad?" John demands, pounding her snatch violently. He drills her, showing her cunt no mercy as he screws her brains out, hitting deeper and deeper with each thrust. Kath can feel him jabbing into her cervix with his large cock.

"Yes! Oh, yes daddy!" Kath screams. "I love your big fucking cock! I love your son so much. I love Tim so much but your cock is much bigger than his! You fuck me much harder than he can! You have a much better cock than your tiny, little cock son!" Talking shit about her boyfriend while his dad is banging her makes her arousal skyrocket. Kath has never been so horny before in her life. She is so turned on right now with her pussy juices flooding out of her pussy in waves after waves, soaking through the couch. "Please cum inside me! I want to feel your sticky cum in my pussy daddy!" she begs her boyfriend's dad.

John eagerly complies. He grunts out loud and starts jizzing inside his son's hot girlfriend, pumping loads of semen into her. The man rapidly fills her up with his seed, burying his cock balls deep in her pussy. Her cunt wrings out more of it until he's done cumming in her tight pussy and stops fucking her. Five minutes later his dick is hard again and ready to go. "I want you on all fours this time, baby," he says. "My son probably never fucked you doggy style, right?" She nods. "Let me show you all the things you've been missing out on from dating my wimpy son."

......

Tim is in a very good mood today. The college sophomore is very happy to be home after another semester is over. He and Kath are in different colleges so the break is a great opportunity for them to spend loads of time together, without having to rely on FaceTime calls. He loves her so much and knows that she also loves him too. Kath is the most important person in Tim's life after his mom died. He used to have a great relationship with his dad, until the old man sent his mother a video of him fucking another woman. That was a real bitch move and he has never forgiven him for that.

Suddenly, he gets a message on his phone. Opening it, Tim is shocked by what he sees. In the video, his beautiful girlfriend is on all fours, completely naked with his equally nude dad behind her, thrusting into her cunt. His hands are groping her massive, ample breasts, squeezing her huge tits. "B B Baby," Kath moans into the video as Tim starts to cry. "I'm s s sorry, but y y your dad's cock is too g g good! I love the way he f fucks me so much! He fucks me much better than you do! He's still f f fucking me right now! Just come home and s s see!" Then the video ends with a clear shot of his dad's cock pulling out of her pussy and her cum filled cunt splayed open for him to see, and he quickly rushes home from the small bookstore.

Entering, Tim could hear creaking sounds from his dad's bedroom. Going in, he is horrified to see that they're still going at it. Kath is holding onto the headboard as she bounces up and down on his father's eleven inches dick, her thick buttocks slapping onto his balls. She turns around to look at him over her shoulder and says "I l l loved you s so much, but I love your dad's cock more. I'm sorry b b but I'm breaking up w w with you! I don't love you anymore. I love your dad's cock, Tim! He's so big. He's a real man, not like you." Her eyes roll back into her skull as she keeps on riding Tim's dad's dick in front of him. She is bouncing so hard that she ends up breaking the bed.

"How could you do this to me?" Tim sobs as he collapses to the floor.

John sneers at the crestfallen sophomore. "Look at this, son," he says, pointing to his massive shaft that he is slamming upwards into the blonde's twat, glistening with her womanly juices. "This is a real man's cock. You don't have one. She said that yours is really tiny and she never felt it once when you fucked her. Well, you're never going to get to fuck her again." He then flips Kath over and gets on top, pounding her orifice very hard as she reaches up above her head to grab the headboard. The broken bed is now a wreck but the two of them don't bother to stop and keep on fucking in front of Tim, until John empties his large balls inside Kath's gripping cunt.

When Josh dismounts her, Kath shows Tim the cum leaking out of her used pussy. "He shot so much cum into my cunt, even after three orgasms," she tells her ex boyfriend. "This is why I can't be with a small cock loser like you anymore. Your tiny dick is nothing compared to your dad's." Then she turns to her father. "Come on, daddy. You can take me to a nice hotel and fuck me there, while we leave this loser here to cry like a baby." Tim's dad laughs and nods. He then gets up from the bed, showing his son how his dick is coated in pussy juices before putting his clothes on. Kath says "You can touch my pussy one last time but with your tongue. Eat your dad's semen out of my cunt." When he says no, she says "Fine. It's probably the last time a guy like you would ever see a woman naked."

Tim goes to sit in his room with tears still streaming down his cheeks. He is at the lowest of low right now, heartbroken and humiliated, seeing no way out of this pit he's descended into. There is no word fit to describe the abject suffering his broken psyche is being subjected to right now. He is feeling worse than he ever felt in his entire life. The way the love of his life so callously threw him away as she rode his father's cock wounded him so deeply and he doesn't even know if he'll ever be able to recover. He might be permanently scarred from the horrifying experience. All he knows is that he has to get out of the house and go somewhere to clear his head.

About twenty minutes after his dad and ex girlfriend left the house, Tim leaves. Even though he was already at the bookstore earlier today, he goes back there anyways. It is the only place where he feels comfortable, aside from his own bedroom, and he doesn't want to be home right now. Tim goes for the science fiction book, hoping to find something that might be able to distract him from the pain. But nothing can. Not even Isaac Asimov's novels could help him right now. He is way too traumatised and ends up leaving after buying Foundation, thinking that maybe by the end of the day, he would be able to read a couple of pages before breaking down again.

He sits down at a cafe, not wanting to go home. He knows that he will have to but not now. Now he would rather just have some latte to wake himself up first. Tim couldn't let himself just sleep the pain away. It isn't a healthy way to cope with depression. It's called running away from his problems and that's not what he does. He's only left the house to get back on his feet first. That's all there is. Now he is ready to go back home and confront his feelings. No more running around like some damn coward. The nerdy college boy pays the bill and leaves, slowly wiping away the remaining drops of tears on his face as he goes.

Once he's back home, he tries to read the book he just bought. He does manage a few pages before starting to tear up again. Stupid tear ducts, Tim thinks to himself. Why must he be so fragile? But as much as he wants to stop crying over Kath, he can't. She wasn't just his sexy girlfriend. She was his childhood friend too. They grew up together! How could he expect to get over her so soon after she hurt him so badly? It is going to take some time. He'll probably end up needing some help. But who the hell would be able to help him with this? Mom is dead and dad just stole his girlfriend and is ploughing her right now in some hotel room while he is sitting here alone at home, unable to even read more than three pages.

The answer soon comes in the form of Penny's arrival. She is wearing booty shorts which shows off her muscular thighs. Of course those legs are very muscular. She is fastest girl on both the swim and track teams, holding the school record for the 100m in both of the sports. Those legs sprinted 100m in 12.96 seconds and swam the same distance in 59.21 seconds. "Hi, Tim!" she says to him before noticing the very solemn expression on his face. "Oh my god! What happened? Are you okay? Did you have a fight with my sister or something?"

Tim has always seen Penny as a little sister, since she is his girlfriend's, or now ex-girlfriend's, little sister. Yes, he knows she is incredibly hot, maybe even hotter than Kath, but he has never had lustful thoughts for her, both since he was dating someone and she was the someone's little sister. It would have been very inappropriate for him to lust for her. He has no idea that she lusts for him though, and thinks she is only being concerned as a friend. "There's nothing for you to worry about," he tells her. "Really, I'm fine. Don't worry about me, Penny."

Penny came over with the purpose of seeing if his relationship with her big sister is still going well. She knows that it's wrong but she couldn't help rooting for them to break up so she could have a chance of being with the only boy she loves. Right now it seems like her wish has finally come true. Nothing could make Tim cry like this except for if her older sister did something really nasty to him. "Bullshit! If nothing happened then why the hell are you crying?" she demands. "Please, I really care about you. Just tell me what's going on so I can help you with it, Tim."

Tim finally realizes that she could be the one to help him slowly move on and get over his loss. He looks at her with his puffy red eyes and wipes away the remaining tears with the back of his hand. "She cheated on me. You heard me right. Kath cheated, and I walked in on them," Tim says. Kath looks super horrified by what she just heard. "I can understand if you don't want to believe me, since she is your big sister. But that wasn't even the worse part." He sighs, his head hanging low in despair as he is forced to fully confront how messed up his situation is.

Penny simply throws her arms around him and lets him cry on her shoulder. "I believe you, Tim. Of course I believe you," she whispers in his ear, stroking his thin back. "Don't ever doubt that. No matter what happens, I will always believe you, over everybody else, even my own sister." She caresses his hair and the oblivious boy doesn't notice how she is sniffing it, inhaling his scent through her dainty nostrils. "She must be such a bitch to do that to you. How could it have been any worse? You said you walked in on them. Was it one of your friends or someone else that you know? That must really suck."

"She fucked my dad," he mutters and Penny's eyes go even wider. Then she starts smiling inwardly. She doesn't like seeing Tim in pain but her sister has fucked up so badly that there is no way to recover from it. "Kath sent me a video of her and my dad having sex and told me to come home. The moment I got there, they were still doing it. He was sneering at me and telling me how much Kath preferred his cock over mine." Tim starts sobbing again and Penny gently caresses him, holding him tight against her. "What did I do wrong Penny? Why would she humiliate and hurt me this way, after everything we've been through together?"