Kims Sister The Slut Pt 07

Recap: My girlfriend, Kim, has an 18 year old sister, Katie, who was kicked out by her parents, and so Katie stayed on Kim's couch. I caught Katie masturbating and got an amazing show and blowjob (Part 1). Kim and I had been fucking in her office, but her secretary, Rita, likely knew our secret (Part 2). Back to the night that I caught Katie masturbating, Kim and Katie ended up in a 69 and I fucked Kim (Part 3). Rita blackmailed Katie and had me fuck her ass while Kim ate her pussy (Part 4). Kim was still a bit hesitant to get involved with other women, but her willingness to indulge in fantasy led Katie and me to plan to make her act on her desires (Part 5). Katie gave me panties from her hot volleyball playing friend, Amber, who I ended up eating out and fucking in front of a satisfied Kim (Part 6). Now, it's time to turn the tables on Katie, who lied.

***************

Katie froze as she saw me sitting on the recliner in her older sister's (Kim's) living room. I don't really blame her because I was sitting in the dark waiting for her like a concerned parent, and there's enough that Katie does wrong to make her always concerned about getting caught doing... something.

"I heard that you're a little troublemaker at school." I opened.

"No shit, that's why I'm crashing on Kim's couch. Speaking of, it still smells like sex in here, so give me the details! Did you guys fuck Amber?" Katie was insatiable.

"I'll give you details, but first I need answers." Katie's face dropped. "I recall that I gave you Kim's panties to give to Amber, but Amber says she never received them. Between the two of you, I'm more inclined to believe her. So." I left the last word hanging with a finality that indicated that it was her turn to fess up.

"Fine, I didn't give her the panties, okay?"

"Then what happened to them?"

"I, uh, kept them. For me." Katie seemed evasive.

"Go get them." I instructed her, my eyes never leaving her face.

"I can't, they're not here right now." Katie was evasive and not very good at it. No wonder she got caught all the time.

"Where could they possibly be? Did you give them to someone?"

"No, I swear! I still have them, they're just not here!"

"Then where are they?"

"Why does it matter?" Katie was really trying to avoid answering.

"Because my girlfriend's used panties are out there... somewhere, being used for who knows what by who knows who. And you have access to photos of where they've been. They could be a valuable little asset, maybe something traded for cash? Blackmail?" I could only speculate on what Katie had done with them, but my best guess was that she sold them for cash. Maybe she even said they were hers.

"No, I still have them, I swear, Rog! I'll give them back tomorrow, okay?"

"Why did you keep them? Do you like them?"

"I, uh, yeah, I love them! I like to recall that night when we fucked and... I can't help it." Katie was not convincing, and I suspected something more sinister.

"So where are they?"

"I left them at my step-mom's house," Katie replied meekly.

"Your step-mom's house? What were they doing there?" I was surprised by her answer, my mind racing to figure this out before the scheming Katie could formulate another lie.

"I brought back a bunch of stuff, including some stuff that, um, my step-mom noticed was missing from her house, and I accidentally left them there." Bullshit, I thought.

"Oh, okay, so right now your step-mom has a pair of Kim's panties that have obviously been cum in in her house and they're there because you just happened to have them on you when you went over there on a Saturday night for some sort of, what was it, family counseling? Is that all?" My sarcastic tone indicated my incredulousness.

"Actually, that's close enough, yes. I don't need to answer this, but yes, and I'll get them back tomorrow. I can't go back there tonight, please! She's such a scheming bitch and I can't handle it right now!" Katie genuinely seemed on the verge of tears.

I contemplated cutting through her bullshit and being bossy (she often listens to me when I am), but I just can't. There's a line between informed, caring consent like I've been building with Kim and just being a demanding asshole, and I won't cross it no matter how much I want to.

"It's okay, Katie, just get them back tomorrow, okay? I'm still pissed that you lied to me, and we're going to have some trust issues, but what's done is done at this point. I'm sure you're not lying now, so let's just move on." I think that did the trick.

"Thanks, Rog, I appreciate it. So, tell me what happened with Amber! I'm dying to know why it smells like sex all over the living room!"

"Hold on a moment, Katie, how did it go with your step-mom?"

"Ugh, fine! It was... interesting. Even in counseling," Katie said using air quotes around counseling, "my step-mom is, well, you've never met her, right?" I nodded my head no. Kim is not close to her step-mom, who came into the scene after Kim was out of the house, and it's obvious why. "Well, she's controlling at all times. Even in 'counseling,' she's always looking for ways to manipulate you emotionally or physically or... whatever."

"What did she do?"

"She just brings up my past bad behavior, like when I would steal from her or when I tried to fuck her ex as revenge for her cutting off my internet access for watching porn or something else. We can't move forward until I 'atone' for my past actions, she says, so it's just her listing her grievances and me trying to repay her." I'll have to remember that she tried to fuck her mom's ex.

"How do you repay her through therapy?"

"It's, um, hard to explain, but it's about me helping her through her issues. But it's kinda personal between us, so I'd rather not say more, if that's okay."

"That's fine. You can talk to me if you need to, Katie."

"Thanks, Roger, now tell me all about Amber finally FUCK!"

"Well, we started talking on the couch, and eventually I ended up cumming on her ass and pussy." Not a lie, just missing about every detail.

"Details, Roger, details! Give me the full scoop."

"I'll give you details if you take off your top," I countered.

Katie grabbed the bottom of her shirt but stopped. "Is Kim okay with that?" Katie knew Kim's feelings about what had happened with us and what was allowed.

"She's fine, yes," I said with finality. "Go ahead."

"If that's what it takes, then look away." I didn't look away. Katie pulled her hoodie over her head, her tank top coming up with it until her large breasts got in the way. Katie then ripped off her tank top (almost literally, she was eager, and the material was so thin I was surprised it held up) and reached behind her back to undo her 36D (or was it 36DD?) bra.

"Hold on," I stopped her. "When I tell this story, you are allowed to touch your breasts and nipples, but absolutely nothing else, do you understand?"

"Is that what you worked out with Kim?"

"Something like that," I lied. I intended to give her every single detail (maybe even show her some pics) slowly and use her pent-up sexual frustration to get her metaphorically eating out of my hand.

"Fine." Katie undid her bra clasp and smoothly shrugged off her bra. Her heavy breasts dropped to their natural position - a slight tear drop sag that confirmed that they were very real. Her brown nipples were already slightly hard. I never really noticed her nipples before, but her areola was bumpier and larger than Kim's and her nipples appeared to be a bit longer as well. I suppose we'll see when she's really riled up.

For the next 15 minutes, I regaled Katie with the story of how I ended up inside Amber. Katie particularly liked the parts where I made Kim stop and wait on multiple occasions. But the parts that really got her leaning forward, hands teasing her hardened nipples, were when I described Amber's body. Every little detail enthralled Katie, from her calf muscles to her taught stomach to her perky breasts to her strong thighs to her firm ass and her gorgeous vulva.

"Come on, Roger, I have to finger fuck myself at least! This is too hot!"

"Nope, you made a deal. You can play with your tits all you want, but hands above the waist."

"Fuuuck, fine! Keep going, though."

I moved onto the part where I forced Kim to sit on her haunches and watch as I fucked Amber right next to her face, alternating between Amber's pussy and Kim's mouth, and only letting Kim taste Amber's cum from off of me.

"Damn, that's so hot! More!"

When I got to the point of us cumming, Katie was practically doubled over, her thighs clenching and relaxing rhythmically as her breathing got shallower and shallower. She was wearing cotton shorts, sort of like loose, thin sweat pants. As she clenched and unclenched her thighs, I could see up the legs and just barely see the edge of her panties. I was nearly as turned on as Katie was.

"Di-did you make Kim clean off your co-cock with her mouth?" Katie asked.

"Yes, but I hardly had to make her. I just pulled out and she opened up expectantly like it was her job." Katie was rubbing both nipples between her fingers. She brought up her right nipple to her mouth and began to flick her tongue across the tip, barely reaching.

"No, Katie, that was not in the rules."

"These rules suck! Come get me off, I need to cum! I've been trying to fuck you for months, let's go already!" Katie was getting desperate.

"Too bad, either you can cum only playing with your nipples or not at all. That's the rule, Katie."

"Yes, sir," she moaned, accepting the roleplay. "What happened next?"

"Why don't you watch what happened next?" I asked. I stood up, my erection clearly evident in my gym shorts. She gazed at my cock while I pulled out my phone, pulling up the photos and videos of Kim cleaning up. I also pulled something out of my other pocket and hid it behind my back.

"Oh my god you did not!" Katie practically squealed in excitement. "You fucking took pics?"

"Something like that." I pulled up a few pictures of Kim licking my cum (and Amber's pussy juice, which was everywhere) from Amber's thighs and ass.

"Oh my god!" Katie was fixated on my phone. She was also twisting her nipples and gyrating her hips.

"Now you've been a good girl with the rules, so I'm going to let you have a little something."

"Fucking FINALLY!" Katie started to put her hand in her shorts.

"No," I stated firmly, pulling out her hand. You can take off your shorts, but no touching yourself below the belt. Katie lifted her hips and slid her shorts off swiftly. Her light purple cotton panties slid down a bit as she did, giving me a quick peek at a tiny bit of stubble where her landing strip would be if she had one before she pulled them back up. Her panties were simple and looked well worn, like a pair of old shoes that just feel good to put on. I could smell and see her wetness, and once again I had to resist the urge to finally taste Katie as I had been longing to do for months now.

As she pulled them back up, she tugged her panties up a few times, nestling them firmly against her pussy lips and giving me a lewd show. Katie knew my kinks and turn-ons, and that view of her 18 year old pussy lips tucked behind her simple but cute panties was one of them. But I was ready for her. "Knock it off, Katie, I know what you're doing." With a huff, Katie sat with her legs crossed (in what used to be called Indian style) and resumed fondling her tits.

"Now, swipe to the left to see the next one." I instructed her. Katie swiped off the last picture in the album to the video that I took of Kim slurping my cum from Amber's asshole and pussy. It was two minutes of straight debauchery, my nigh-slave girlfriend eagerly licking my cum off of another woman's pussy. As Katie watched, I pulled Amber's panties out from behind my back and brought them up near Katie's face.

"Are those Amber's panties?" Katie's eyes lit up even more. She clearly had a thing for Amber. Not that anyone wouldn't, but Katie had been close with Amber for a while, and had probably been fantasizing about Amber for just as long. She kissed, licked, and smelled them as she watched her sister eat my cum from Amber's holes, her hands roughly groping her tits and mangling her nipples. "Oh my god I'm going to cum YEEEEESSSSSSSSSSSSSSS!"

As Katie's hips bucked off of the couch and she began her nipple-induced orgasm, I grabbed her hair and forced her to continue watching Kim's clean up. My cock was only inches from her face, albeit behind my shorts and underwear, as I leaned into her ear to tell her, "cum for me, my little slut, cum." She was already cumming, of course, but my instruction had the desired effect of pushing her further over the edge.

"I'm cumming sir I'm cumming I'm cumming I'm cumming oh FUCK sir I'm cumming!" Katie confirmed the obvious. I continued to hold her hair through her orgasm. As she came down, I released her hair. Katie's eyes focused on my cock just inches away from her desperate mouth. I looked down at her and shook my head no.

"Now, since you lied about Kim's panties, you have a new task. Take the panties that you're wearing right now and give them to another woman. It can't be Kim, and it can't be Amber. Those are the only hard and fast rules, but I expect that you'll choose with a goal in mind. You decide what that goal is, but don't lie to me again, Katie."

"No, sir, I won't."

"I expect not. Get me Kim's panties back tomorrow, and get your panties to another girl by, say, next Friday?"

"Deal," Katie said, extending her hand. I shook it, formalizing our agreement. "But what about what I want?"

"What do you want, Katie, and why am I going to give it to you?"

"You know that I've been dying to fuck you, Rog. Ever since Kim first told me about you, about how you made her cum, about how she turned to putty in your hands. She wants nothing more than to be used by you, and I want to know how that feels."

"Well, Katie, that's up to Kim. If she says that I can fuck you, then I'm game. But so far, she's not given permission."

"But you had sex with Rita AND Amber!" Katie retorted.

"With Kim's implicit permission, yes. So don't try to convince me. Convince Kim."

"Yeah, cause 'hey, Kim, I really want your boyfriend to fuck my brains out' is going to work." Katie was not letting it go.

"Obviously, you'll have to do better than that. I saw how you set up the Amber thing," I continued. Katie raised her eyebrows with an amused expression.

"Do you, now?" She said with a gleam in her eye. "What do you think you know."

"Stop, Katie, you know that you were engineering us with Amber for plan of your own. I don't know the specifics, but I'm not blind."

"Guilty, Rog, guilty. But it's not quite what you think. Anyway, I'll try to think of something creative, but I might need your help."

"Well, ask away, but I'm only going to do so much. I'm not going to make Kim feel forced."

Not yet

, I thought to myself,

although if Kim keeps going down this path, she's going to end up doing whatever I want anyway

.

"Anyway, I'm off to bed." I started walking down the hall to Kim's room. "Good night."

"Night, Rog."

******************

The next morning, Kim and I went out to a nice brunch along the waterfront. The spring air was breezy and refreshing, so we sat outside as we ate. A handful of joggers ran up and down the boardwalk as she sipped a mimosa (I had a bloody mary) and we enjoyed a hearty breakfast.

"What happened after Katie got home last night? I heard you two talking for a bit." Kim had already asked about what happened with Amber after she had gone to shower and go to bed (not much, just cleaning up and Amber taking Kim's panties with her). Now she wanted the other details.

"Nothing much. I asked her about her therapy with your step-mom," I started.

"That bitch!" Kim muttered under her breath.

"Yeah, that bitch. Anyway, I heard about that for a bit, then she insisted on hearing all about what happened with Amber."

"Did you tell her anything? What did you tell her?" Kim seemed a little panicked.

"I mean Amber was introduced to us by Katie and they're friends, so she was probably going to hear it from Amber anyway. So, I told Katie about what happened." I looked directly at Kim, who seemed a bit uncomfortable.

"Everything?" Kim asked.

"Everything." I replied, looking at her coldly. I tried to maintain my steely composure, but I wanted to ensure I didn't hurt Kim. "Dragon, Kim." I said her safeword.

"What?"

"Dragon. No role play, no games, let's just talk. I want you to be comfortable, but I also want to push your boundaries. Right now, I'm not pushing. I want to hear from you."

Kim was slightly taken aback. "Well, thanks, Roger, for letting me speak!" Kim is a successful, smart, driven woman, and while she clearly enjoys submission in the bedroom it's a bit harder for her to accept in other scenarios. "Although, if I'm being honest, it's touching how you are concerned about me even as you're using me as a personal glory hole sometimes."

"El oh el." I deadpanned.

"Fine. Honestly, I think I'm okay with it. I don't want you fucking around with other women outside of our relationship, but what we did with Amber was... fucking hot! I was thinking about it all morning. She's obviously gorgeous, and I obviously have some compulsion to... enjoy what we did, so I indulged it. By the way, I noticed that you took Amber's panties at some point. Not sure how I feel about that."

"If it makes you feel better, I took them for Katie's temporary use."

"Um... okay, I guess. I mean, if I'm being totally honest... I want them back. It's painfully obvious at this point that I go wild for panties, or at least hers. This is all new and weird to me, but I've been thinking about it and I want to see where this goes."

"I already put them back," I explained.

"Okay, fine. Anyway, I enjoyed what we did with Amber, and I can't stop thinking about when you alternated between Amber and my mouth. It was so... degrading to be used like that to clean your cock of another woman's juices, but I just couldn't help how hot it was. Like intellectually I wanted to reject it, you know, but physically and emotionally? I fucking loved every second." This was a much better reaction than when we had messed around with Katie and Rita, where Kim seemed to have doubts after the fact.

"Good, I was really trying to pay attention to what you enjoyed and work within that framework. But to be honest, Amber was so hot I would have eaten her out regardless!" I pushed just a bit, "dragon" or not.

"Oh, she absolutely was, and next time I want to get some time between her thighs, too!" Kim's realized that her voice was getting a tad excited for a restaurant, blushed, and gazed down at her plate.

"Okay, settle down a bit or we'll have every mom in this restaurant calling for our heads. How did you feel about the pictures and video."

"I feel like you better show them to me later today when we fuck," was Kim's reply. That's clear enough.

"So, anyway, I told Katie everything," I continued. "Everything."

What kind of fucking hornball wants to hear how their sister was getting sexually humiliated with an 18-year-old and her boyfriend?

Kim wondered.

"Dragon?" I simply asked her.

"No more dragon, baby, I know you love me and I'm getting excited to see what you'll do next!" Seriously, just get Kim a little horny and she's into full obedience mode almost right away. Progress.

"Good. I made Katie take off her top and play with her tits while I told her about how I, we, excuse me, fucked Amber."

"You WHAT?" Kim yelled loudly enough for people to look over. Maybe I'd pushed too far, but it was time to control the situation with, well, control.

"Kim," I said firmly but quietly, "sit back, lower your voice, and listen to what I'm about to tell you so I don't have to repeat myself. I'm sure you're going to love it in the end." Kim sat back, adjusted her hair, and accepted her fate.