The Mother-Fucing Side-Effect

Hal sat at his desk, working through a long list of emails, when his phone buzzed. Glancing at the screen, he saw his wife, Carol's, name and immediately felt a pang of worry. He picked up the call, the bustling noise of the office fading into the background.

"Hey, honey," he said, trying to keep his voice steady.

"Hi, Hal," Carol replied, a twinge of concern in her voice, "We just left the doctor's office. They prescribed a new medication for Gavin, and the doctor thinks it could really help with his depression."

Gavin was their eighteen-year-old son with a bright future ahead of him, or at least that's what they and everyone used to think. Tall and lean, with a mop of dark hair that constantly fell into his hazel eyes, he had always been the life of any room he walked into. But over the past year, something had changed. The spark in his eyes had dimmed, and he had withdrawn into himself. It broke Hal's heart to see his once-vibrant son struggling with depression.

But Carol's words lifted some of the weight off Hal's shoulders..

"That's great news," he said, smiling.

"It is..." Carol agreed, but Hal sensed some hesitation in her voice, "though, the doctor did mention there are some potentially significant and... unusual... side-effects. I'm a little concerned about that."

Hal frowned, understanding her apprehension.

"Well, if this medication can help Gavin, we just need to be prepared to handle any side-effects. We'll do whatever it takes to help him through this."

Carol sighed softly, the sound of her exhale filling the silence between them.

"You're right. We'll manage it. We're stopping at the pharmacy now, see you at home later."

"Okay, love. See you later," Hal said, hanging up the phone, the last few hours of his workday having just gotten much better.

---

Hal drove home with a rare sense of optimism. The news about Gavin's new medication had lifted his spirits, and he couldn't help but hope that this might finally be the breakthrough they needed. The late afternoon sun bathed the neighborhood in a warm glow as he pulled into the driveway, parking next to Carol's car. He stepped out, feeling a lightness in his step that he hadn't felt in months.

Entering the house, Hal called out, "Carol? Gavin? I'm home!" but was met with silence. He frowned slightly, expecting them to be around.

As he took off his coat, he heard faint noises coming from the living room. His curiosity piqued, Hal walked toward the sound, the noises growing louder with each step: a thumping noise like furniture banging against the wall and a strange, wet, slapping sound.

Reaching the living room he turned the corner and froze, his eyes widening in shock at the scene before him. There was Gavin, his teenage son, naked from the waist down as he absolutely plowed Carol from behind.

Hal's jaw dropped, his mind slowing things down as it tried to process just what the fuck he was seeing. Carol, his wife of twenty years, was bent over the front of the couch with her pants at her ankles while his son, HER son, held her by the hips and humped her hard and fast.

Joining the thumping and thwapping noises he'd heard (and now understood) on the way in were short, exasperated gasps from Carol as Gavin fucked the wind out of her, and strange, animalistic grunts from Gavin as he swung his skinny hips into her, hard.

Carol's blouse was still on but hanging loosely, offering peeks of her soft, wobbling tits. Her full, round ass was quaking and rippling with every thrust from Gavin. Her head was hanging down, her hair disheveled.

It felt like eternity but was really only a few seconds of watching before Hal finally found his voice.

"W-what the fuck is going on?!" He stammered, the words catching in his throat.

Gavin looked at him first, with a cold, emotionless expression that gave Hal a chill in his spine. Carol's head popped up an instant later, looking frazzled and a bit dazed.

"H-h-hi, h-h-honey," she said, tripping over the words each time Gavin slammed into her, "I c-c-can expla-a-ain."

Hal registered her words but didn't know what to do with them. They were still fucking! He was standing right there and they were still fucking! And also, why the fuck were they fucking fucking?!

"WHY ARE YOU FUCKING??," demanded Hal. He would've added "my wife" or "our son" or "your mother" to the end of his question, but since all applied his brain couldn't pick one fast enough.

Carol adjusted herself into a slightly more upright position where Gavin's thrusts weren't shaking her whole body quite as much. She tried to wipe and blow the hair from her sweaty face, but it did little to help her disheveled appearance. Gavin didn't slow down at all and was still pounding his mom's pussy like her husband wasn't fifteen feet away.

"It's the new medication," said Carol, her voice relatively steady, "I told you the side effects were extreme."

It took Hal a few seconds to remember anything that had happened before he'd walked into this room, but the earlier phone call with his wife did eventually return to him.

"Side-ef... fucking... WHAT??" Hal shouted, confused and still shocked as hell.

"The doctor called it, ungh... hyper-virility," said Carol, grunting through a particularly deep thrust, "it's like a fugue state where the user is really, really, really really horny. He doesn't even know what he's d-doing, his body is just telling him to fuck anything that m-moves."

Hal's brow furrowed in disbelief. Hyper-virility? Doesn't know what he's doing? He'd believe it more if she'd said they both accidentally tripped and ended up in this position.

But as he looked again at Gavin's face, the vacant eyes, the almost bestial sneer, and the total lack of acknowledgment of Hal's presence, he knew that, some-fucking-how, what Carol was saying had to be true.

Gavin's head dipped to the side and he grunted before plowing into his mom's pussy even more forcefully than before, causing her to moan in... pain?

"So, like, right now? He... doesn't care that he's fuc- I mean, that you're his...?" Hal stammered out his words, not knowing what one should say when seeing one's wife getting used as a living sex toy by their own son.

"Apparently n-not. The doctor advised to k-keep him away from anyone that he m-might get too amorous with. I u-underestimated the strength of these m-meds, I guess," she said, her tits rocking back and forth as Gavin continued his assault.

"Well why doesn't he- why couldn't he- ... I mean, couldn't he just, y'know, masturbate?" said Hal, trying to logic his way out of his son plowing his wife.

"That's what the doctor suggested, but there's no reasoning with Gav in this state. Believe me, I've been trying," she said with a hint of annoyance, "and if you'll remember, it was YOU who said not to worry about the side-effects, that we'd help him through it."

Well, this was certainly the worst way Hal had ever been hoisted by his own petard: having his wife hoisted on their son's.

"So... what? He just fuc-... just has sex with you and he orgasms and then he's fine?" said Hal, though the pit in his stomach knew it wouldn't be that easy.

"I wish," said Carol, bracing herself as Gavin pawed at her big, hanging tits through her blouse, "this is round three and there's no s-signs of him slowing down."

Hal's heart skipped a beat.

"You've fucked him three times??" he shouted, losing what little composure he had left.

"No, the first time was a hand job. Twenty minutes after he took the meds he came up behind me in the kitchen and had his hands all over my ass and boobs. When I figured out what was going on, I offered the hand job to keep him from tearing my clothes off. He... came... pretty quickly, and A LOT, but it didn't stop him. He seemed to need more so I used my mouth on him the second time. He liked that more than the hand job and he came again, so I thought I was in the clear but he just kept tugging at my pants until I gave in. Now he's been fucking me like this for the last half-hour!"

Hal stood in stunned silence. So much to take in, and the rhythmic sound of his son's pelvis smacking against his wife's ass wasn't helping. The air was heavy with the musky scent of sex. He could... accept, that this was something that needed to happen, regrettable as it was. But he didn't think he could stomach being around it any longer.

"I..." he started, searching for the words, "I get it. Thank you, for looking after our son."

Carol gave him an unhappy sort of smile, a sign that she appreciated his words but knew how much the situation sucked.

"I think I'll just go upstairs, or go for a drive or something," said Hal, rubbing his eyes in the hope the image in front of him would be wiped away.

"Wait! Don't go!" said Carol, "I need you, WE need you close by in case something goes wrong. What if he hurts himself? I won't be able to handle him alone."

It seemed to Hal that she was handling him just fine, but he saw her point. Painful as it was for him, it was surely no walk in the park for her, either.

"Ok, I'll just, uh, sit down," said Hal, feeling awkward now that the heightened emotions of the situation were lowering.

He sat on the lounge chair across from the couch. From this angle, he was seeing a lot less of his wife and a lot more of his son's bare ass. It certainly wasn't top of mind, but he noted how muscular Gavin's legs and glutes were. His son had always been an athlete, and was now over six feet of lean muscle, with four inches of height on Hal himself.

Gavin gave one last, deep thrust into his mom's pussy, smacked her hard on the ass, and pulled his cock out of her. And Jesus, what a cock. Height wasn't the only place Gavin had four inches on his old man. Hal's eyes bugged out as he saw the thick, meaty pole slide out of his wife and bob around as Gavin flipped her over so she was laying on the sofa. Pushing her legs wide, he plunged that fat cock back into her with a wet THWOOP and a groan from Carol.

Gavin quickly resumed the pace with which he'd been fucking her doggy style. Her blouse had twisted so much that her boobs were practically falling out of it and Gavin finished the job, tearing the blouse slightly to get at his mom's milky jugs. He grabbed big handfuls and squeezed, kneaded, pinched and shook them, never slowing his ravaging of her pussy with that enormous cock.

Carol was breathing hard, from exertion Hal supposed. She was taking the brunt of one hell of a fucking.

"S-so..." she stammered through Gavin's humping, "h-how was your day?"

Perhaps never had something so banal been said in such an un-banal situation. It actually surprised Hal so much he was answering before he could recognize the absurdity of it.

"Umm, it was fine, I guess..." he said, watching Gavin's smooth, heavy ballsack slap against Carol's asshole, "actually there was one sort of interesting thing with the layout for the August catalogue. Do you remember I told you about that guy from the..."

Hal droned on about his work story, finding that it was distracting him from what was happening. Carol seemed to be listening intently at first, but not so intently the longer he went on. Hal watched as her eyes started to glaze over, then roll back into her head as a long, loud moan escaped from her chest.

"OOOOOHHHHHHFFFFUUUUUGGGGHHHHKKK!" she bellowed, her cheeks flushing, her legs shaking, her son pounding her cunt with his thick slab of man meat.

The moan was followed closely by a few light giggles, that Carol quickly swallowed as she regained some amount of control. Hal watched her face return to normal, his own wrinkling into a nauseous look of horror.

"Did... did you just have an orgasm on our son's cock?" he asked, more rudely than he probably should have but, well, there ya go.

"It's not my fault!" cried Carol defensively, "You try getting fucked like this for nearly an hour. Son or not, a few orgasms are going to slip through."

Hal choked on his own saliva. A few...?

A loud grunt from Gavin kept Hal from pursuing the thought. His son's pace was quickening, his fucking of his mom's soaking pussy getting more erratic. He stayed on edge for a long time, nearly a minute more, but the third orgasm he'd apparently been building toward erupted deep inside Carol's pussy, flooding her with molten cum as he smashed his pelvis into hers, trying his best to deliver it to her womb.

The rhythmic pounding that had led Hal to the room had finally stopped. He watched in awe, waiting to see what would happen now. Both Gavin and Carol were panting hard, catching their breath after the marathon session. Sweat glistened on their exposed skin and made what little clothes they still wore sticky and clingy. Gavin left his cock inside his mom for another minute or more, and Hal would occasionally see his balls tense, depositing more and more of his seed into her.

Eventually, Gavin retreated his hips and let his cock slide out of his mom with a PLOP. The creampie he'd left her followed in short order, oozing slowly from her opening like thick, melting ice cream.

"Is... is that it? Is it over?" asked Hal, hopeful that this nightmare was ending.

Carol was staring up at Gavin's face. His eyes were closed, his head dipped as he continued trying to catch his breath. His fat cock was still looking mostly erect, but not quite as dangerous as it had before.

Carol sat up on the couch, Gavin standing in front of her.

"I think he's-OOOP!" Carol was cut off as Gavin grabbed her by the back of the head and pushed her mouth down on his cock, which was quickly regaining its full strength.

"Shit" thought Hal, realizing the ordeal wasn't quite finished.

He watched for a couple minutes more as Gavin's face-fucking of Carol slowly turned into more of a vigorous blowjob as she recovered from her initial surprise and tried to get some control over him. He wouldn't let her stop or even slack off too much, and would grab her hair and pull her back down on his member anytime he seemed to feel she wasn't performing the task well enough.

"Igh fingk heeg's onnag nee juspa liggle bidt morghp," Carol said through a mouthful of her son's cock. Hal couldn't fully interpret but got the message anyway.

"I'm gonna get started on dinner," he said, rising to his feet, "I'll be just in the other room if you need me, and I'll check back as often as I can."

Carol's mouth was getting fucked again, so in lieu of a verbal response she gave a quick thumbs up to her husband before putting her hand back on Gavin's hip to try and steady his pace. Hal retreated from the room with the parting image of his son pushing his cock into his wife's throat.

The sounds of Carol sucking off their son, a mix of wet smacking noises and guttural gags, followed Hal into the kitchen. As he began pulling together ingredients for the family dinner, he did his best to push it from his mind. A shift in the noises from the other room a few minutes later sent him back in to check on them, finding Carol with her head down on the floor and her ass in the air as Gavin munched hungrily on her asshole. Her face was contorting as though she was trying (and failing) not to enjoy the sensation of his tongue deeply rimming her. Gavin was crouched behind her, his glossy eyes and the raging erection he was pumping with his fist a sign that this was more about his desire than her pleasure.

Hal left the room again, taking his time chopping some vegetables in the hopes they'd soon finish up. Around ten minutes later, he went to check on them again, finding Carol flat on the floor with Gavin reverse-straddling her face, his strong hands mashing her huge tits together as he jug-fucked her. He was playing with her tits, slapping them around as his fat, spit-coated cock penetrated her cleavage. His heavy balls dragged across her face in-time with his thrusting as Carol feebly stuck out her tongue to service them, licking his taint just as often. It seemed like this was heading in the direction of her being pressed into returning his rimjob favor, and watching his wife lick his son's asshole wasn't something Hal cared to see. He made a hasty retreat back to the kitchen.

The sound of Carol loudly exclaiming "No!" brought Hal hurrying back in a few minutes later. There he found Carol back on her knees with Gavin pounding her doggy style. Her eyes caught her husband's, seeing his look of concern.

"He tried to stick it in my ass," she said, a little shakily but with the nonchalance of someone who had just avoided spilling their coffee, "but I told him to do me in the pussy instead. He seems to respond if the request is made a certain way."

Hal noticed that though Gavin's cock was in her pussy, he had a thumb buried past the knuckle in her butthole, working slowly in and out. Carol turned her head slightly back toward him.

"That's it, fuck me in the pussy, baby," she said like a mother gently coaxing her son to, well, keep fucking her pussy and not her ass.

Hal walked back to the kitchen to finish the dinner, relieved (he guessed) that his son hadn't anally fucked his wife.

"Yet," he mumbled to himself. This was day one of god knows how long Gavin would be on this fucking medication. So many lines had already been crossed to appease him, it seemed like only a matter of time before more would be.

Hal shuddered at the thought, busying himself with the final bit of dinner prep.

Another ten minutes later, the food was ready and Hal prayed the rest of the family was ready to eat it. He was almost relieved as he re-entered the living room to find that Gavin was on his feet, rapidly jacking his cock as he aimed it at Carol's face as she knelt in front of him.

The look on Carol's face was one of accepting, even yearning, for her son to cum on her face. Hal could hardly hold it against her; she'd been trying to sate the sex-monster for hours now, and maybe this load of cum would be the one to finally do it.

Hal cleared his throat awkwardly.

"Dinner's ready," he announced quietly, suddenly feeling like he was intruding.

Carol glanced at him and gave a subtle nod of recognition. She was naked now, the tattered blouse having finally been chucked away. She was holding her heavy tits from beneath, offering their fleshy visage to Gavin, trying to entice him to coat her in jizz. Tentatively, as though knowing it might help but not sure if she ought to, Carol opened her mouth and stuck out her tongue.

That seemed to do it. Gavin's strokes became faster, his hand gripping his cock like a vice as his whole body tensed. Hal saw the veins in his arm and cock bulging, his breath becoming shallow and ragged. Carol's gaze was fixed on Gavin's dick, her eyes averting slightly as if she were looking at a grenade that was about to go off.

With a loud, primal groan, Gavin threw his head back and started to cum. His wad erupted from his angry cock in a thick, white stream, splattering across his mom's pretty face. Her lips, her cheeks, her tongue, her forehead; all were quickly coated in criss-crossing ropes of her son's hot spunk. A glob landed across her eye and another streaked through her hair. What didn't catch her face landed in a pooling mess on her round, sweaty tits.

It was a majestic, sweeping symphony of a cumshot that surpassed any Hal had seen in years of watching porn. Any two of the facials he'd given Carol during their marriage couldn't compete with the incredible volume of the load their son was frosting her with.

And yet it was not jealousy Hal felt, but relief. Surely, he thought, watching Gavin squeeze the last few spurts onto his mom's coated tongue, surely this was the end of it.

"Cagh youg geck megh ah towlruh?" mumbled Carol through a mouthful of her son's cum that she understandably didn't want to swallow.

"Oh, yeah, right," said Hal, snapping out of his trance. His wife needed a towel and neither of them wanted Gavin's cum covering her any longer than it had to.