To your sister-in-law's house

You pulled out of your driveway and onto your street, turned left at the first intersection, then started making your way across town towards your older brother, Brandon's, house. His wife, Kelly had called you earlier in the week to ask if you could come over to help her move some furniture and you had told her that this morning was what worked best for you. Your brother is apparently away on business, she forgot to have him help her before she left, and she has an appointment to have their carpets cleaned on Monday. You and your brother have never been terribly close, going back to even when the two of you were younger. He's always been the type to brag about how much money he makes and likes to belittle people, but you've always been fond of Kelly and, honestly, thought she was too good for him.

Pulling into their driveway, you exit your car, walk up to the door, and ring the doorbell. You wait only a few moments before the door opens and you're greeted by the smiling face of your sister-in-law, who embraces you in a warm, welcoming hug.

Kelly is only 5'3", so the top of her head only comes up to your chin and, as her still-damp, curly, brown hair gets close to you, you get a whiff of the scent of her fruity shampoo, letting you know she just recently showered. The hug isn't one that lingers and when the two of you separate, you can see she's dressed to help with the work, wearing a pair of grey leggings and a baggy sweatshirt, so rather than waste time with small talk, you asked her what needed to get done.

Fortunately, there was only one room, the office, that needed to be cleared out. The objects that needed to be moved weren't especially heavy, just awkward enough to require two people to lift and carry them, so the two of you working together managed to finish the job in under an hour, without even working up a sweat.

After finishing, Kelly offered you something to drink, which you accepted, and the two of you went to the living room to sit and talk. You had anticipated the work would take longer than it did, and hadn't made any plans for the first half of the day as a result. With nothing else to do, you thought it would be nice to chat with your sister-in-law for a bit. As the two of you make small talk, you thought, not for the first time, how easy it was to be around her and enjoyed how quick she was to genuinely laugh at some of your work and school stories. The way her green eyes disappeared and her bright, white teeth showed when she smiled matched perfectly with her natural, inner and outer beauty, and there had been times in the past where you thought if circumstances had been vastly different, you could see the two of you being in a long-term relationship together.

"So, enough with my stories." you said during a pause in the conversation "What's been going on with you guys? It sounds like Brandon's been away for business more and more. What have you been doing to keep yourself occupied?" you asked, wanting to hear more about her.

The question didn't get the response you thought it would, though, and the bright smile that was on her face vanished in an instant, replaced instead with a cold scowl. "Yeah, he has been away a lot more, but it's not all business, it's for his pleasure too." she said, with a distinct and disgusted emphasis on the word "pleasure". "The bastard has been cheating on me!" she revealed, and you saw her eyes become watery as she tried to maintain her composure.

This statement surprised you. You knew your brother used to fuck around a lot and cheated on plenty of old girlfriends, but you figured now that he was married, he'd put that behind him. "Whoa Kelly, where's this coming from? What makes you think he's cheating on you?" you ask, talking her hand in yours.

"After his last business trip, I looked in his luggage before doing the laundry to make sure there wasn't anything he had forgotten to unpack and found a thong in his luggage." she said, becoming more upset as she recalled the story and you saw a single tear for and roll down her cheek.

"Is it possible they were just old? Could they be yours?" you asked, not really sure why you were trying to defend your brother's integrity.

"No. First of all, they're not my size. Second of all, you could tell they had been worn recently. They still smelled like that skank's pussy and there were dried juices on the crotch. And before you ask, that's not the only proof I have. The dumbass is actually messaging this whore, sexting her, telling her how much he can't wait to fuck her again, and exchanging nudes. It's not like I didn't know that he had it in him to be a cheater. Hell, he was dating someone else when I started fucking him, and I also know about him fucking that stripper at his bachelor party, so it's not like he hasn't cheated on me before either. I guess I'm just the idiot for being stupid enough to believe him when he told me "he was wasted and not thinking clearly", and that it was "just a one time thing. A last hurrah before he dedicated himself to our marriage." I guess I deserve it for being the "other girl" myself. Karma's a bitch, isn't it?" she said as more tears joined the first, then she dropped her head to her chest, looking deflated.

Another surprise, hearing that she knew about the stripper, and you wondered how she found out. The only people who knew in addition to you were, obviously your brother, and a few of his old, college, frat brothers. They were the ones that had hired the stripper for the after-party and paid for him to get "a little something extra", but they were also, generally, a group of loud-mouthed morons and you wouldn't be shocked if you found out one of them had let that information slip. "Well, if he's cheating on you, he's an idiot!" you said, realizing the "how" wasn't really important. "I've honestly thought you were too good for him since I've met you. You're sweet, bubbly, fun to be around, smart, contribute financially, and you're sexy as hell! I know I'd be more than happy if you were the only person I could fuck for the rest of my life." you told her, trying to boost her self esteem, getting a little pissed that your brother was making her feel this way about herself.

"Well apparently I'm not enough for him. And if he's not going to keep our vows, I sure as hell don't plan on it either!" she said, straightening up and wiping away the remains of the tears from her cheek. "How'd you like to be the first one to help me break my marriage vows?" she then asked, reaching over and placing her hand on your crotch.

Despite being taken aback by her sudden change in mood, you felt yourself stir at the offer, but managed to offer some resistance, knowing that there's no way any good could come from going through with this. "Kelly, let's not doing anything rash. You're hurt and angry, but think about what you're suggesting." you said, gently taking her hand to move it from your genitals.

"Oh, I've thought about it plenty. I came to you because I thought you'd appreciate the chance to get back at him for being such an asshole of a brother to you for all these years. Besides, I've got some additional information that involves you that you might find interesting and might like to know about before declining my offer. Do you remember that girlfriend of yours he had sex with when you were in high school? Well, it wasn't a mistake like he told you. He knew exactly who she was and did it just to be a dick." she told you, slipping her hand free from your grip and placing it high up on your inner thigh.

"What are you talking about? You mean Jessica?" you asked, recalling the cheating whore you dated for a while. "That was over ten years ago. How do you even know about that?"

"Well, one night, when he and his friends were downstairs in the basement drinking, I went to the kitchen to get myself a glass of water. By this time, it was getting late, they had obviously had more than a few, and were getting loud and obnoxious, talking about their glory days and all their former conquests. I moved to close the basement door to block out their noise so I could get some sleep, but stopped when I heard Brandon start bragging about how he had fucked one of his brother's girlfriends at a party that you had thrown when you were still in high school. I knew I didn't want to hear the details but found I couldn't pull myself away from the door and listened as he told them how your girlfriend was obviously plastered and he decided to hit on her, just to see how far he could get with her. He went into detail about how she ate up the compliments he had given her, telling her how sexy she was and how she could probably have any guy at the party that she wanted. He boasted about how easy it was to steer the conversation towards sex and eventually asked her if she'd ever been fucked by brothers before, then asked if she'd like to find out the things the older, more experienced brother had learned at college. He told them how he fucked her in his room while you were in the same house, none the wiser, then laughed out loud when he recalled how you found out a week or so later but were gullible enough to believe him when he told you he didn't know the two of you were dating."

"I haven't been able to look at him the same way since I heard him brag about doing that to you, and I think I'm finally starting to realize what an asshole I've married." Kelly said to you, repositioning herself so that she was now sitting facing you and placed her other hand on your opposite thigh. "I've always thought you were pretty hot, David, and if I'm being honest with you, there's been more than a few times that I've masturbated thinking about you. I figure if he was fine with sharing women with his brother back then, why not now? I'm going to cheat on him, David. I'd prefer it to be you, but if not, it's going to be one of his friends, or maybe more than one of them. C'mon we can both have our **** together." she said, moving her hand back to your crotch and rubbing you through your shorts.

Temporarily taken aback by this new bit of information, you began thinking back on the day that you found out Jessica had cheated on you. It turns out, there were more guys than just your brother she had fucked, so when your brother claimed he didn't know you the two of you were dating, and that she was the one that threw herself at him, it was easy enough for you to believe him. Kelly's story, though, sounds like the more likely one and the anger you thought you had let go years ago, came bubbling back to the surface.

Kelly took your silence, as you sat there stewing, as an ok to continue and pulled herself away from you to pull her sweatshirt off over her head, revealing to you that she had not been wearing a bra. You couldn't help but stare at the site before you as you got your first ever, unobstructed view of your sister-in-law's tits, and fuck, they were nice. Heavy, with a natural, tear-drop shape to them, they pointed slightly up and out to the side and looked to be a healthy C-cup, or maybe even a D. Triangular shaped tan lines were visible on each of them, and she had light-pink areola the size of quarters centered on each breast with petite nipples that were half a shade darker.

Seeing you unblinkingly staring at her chest encouraged Kelly to continue. "Do you like my titties, David?" she asked as she lifted one with her hand and pinched her nipple between her thumb and forefinger. "Have you ever fantasized about playing with them? Maybe about sucking on my sensitive little nipples, or maybe having them pressed on either side of your head, or maybe you've thought about shooting your hot load all over them while I'm on my knees in front of you. Would it turn you on to know that I was thinking about those things and more last night while I rammed my dildo in and out of my pussy? I was fantasizing about all of the things I wanted you to do to me today and screamed out your name when I came. We can do anything we've ever fantasized about doing to each other right now, David, while we hurt that asshole like he hurt us. All you need to do is tell me you want to." she suggested to you, maintaining eye contact as she started bending down and bringing her mouth closer to your rapidly swelling member and her hands began tugging at your button and zipper.