Sister in law SeXStoRY

My wife's s****r lives next door to us, and being a single mom it's not uncommon for her to call me up during the day, asking me to come over to help with something or other. I work from home, so I'm home most days, and it's no trouble for me to go over. Plus, she's kind of cute in a chubby little s****r sort of way, and I have a thing for damsels in distress. So one day she called me and said she needed my hand, and could I come over? Sure, I said, be right there. I threw on a pair of pants and a shirt and walked across. She met me at the door, and after a couple minutes of small talk I asked what she needed help with. "I just need your opinion as a man," she said. "I have a date tonight, and I want to know if the outfit I picked looks good on me, and I know you'll be honest with me." Okay, I'm thinking, this could be nice. Date means a dress, or maybe a skirt, and I'm never one to look away from a well dressed lady. That, and I'm wondering who the lucky guy is. I didn't know she was dating, but then again, it kind of sounds like a first date situation. "Sure," I said, "do you want me to look at the outfit by itself, or were you planning on modeling for me?" "Just sit right there, and I'll be back in a minute." I sat on the couch with a glass of tea, wondering what she might wear. Se doesn't usually ask my advice on clothing, but maybe this guy is special. Of course, if he's anything like me, he'll probably just want to see her in as little as possible. I chuckled quietly to myself at the thought. "Okay, I'm about to come out. But remember, I don't have any makeup on or my hair done, so just look a the outfit, all right?" I promised to be as objective as possible, and she opened the door. My mouth dropped, and all I nearly choked on my tea. She was dressed about like this: I stammered, "You're going on a date in that?" "Mm-hmm," she winked, "right now, and you're the lucky guy. So, how do you like it?" I just kept staring, wondering if this was some sort of set-up with my wife. As if reading my mind, she answered my thoughts. "She didn't set this up, it's completely my idea, and she never has to know. But I knew you were home, and I'm horny as hell and haven't been laid in months, so I figured hey, what the hell? Now, either you come fuck me of I'm telling my s****r that I caught you in my back yard peeking into my bedroom window while I masturbated." She said it with a wink, but I knew she meant it. Might as well, I thought. An opportunity like this doesn't present itself that often, and she's got as much to lose as I do. With that, I stood up, pulled my shirt up over my head, and unzipped my shorts. What a day to go commando, I thought! My cock was so stiff it made it hard to get the shorts down over it, and by the time I was naked she was in her bedroom on the bed, with the sheer panties pulled to one side, lips glistening. I walked in and stood between her legs, noticing that the bed was the perfect height for my cock to hit her pussy. Nice, I thought, as I leaned over her and kissed her, letting my cock slide easily into her sopping wet snatch. She moaned and wriggled herself against me, then kissed me back and said, "What, no foreplay, baby?" I was a bit ashamed - after all, I do generally want to please my partner first, but she'd seemed so eager - and I started to pull out. She grabbed my ass and said "Oh no you don't! That hard cock isn't leaving my cunt until it's soft and I'm full of cum. Got that, buddy?" Yes Ma'am! I love it when a woman knows what she wants. Without any further hesitation, I cupped her tits in both hands and pounded her pussy as hard as I could. She almost screamed with pleasure. "Damn, you're wet," I panted. "It feels like you've already been fucking for an hour." "I have, baby, I have. I came twice on my dildo before I called you, and I was fingering myself while I watched you walk over. And I'm about to again, if you'll shut the fuck up and ram that cock where it belongs." Never one to disappoint a lover, I did as she asked, pinching her nipples and thrusting my cock so hard into her that I hurt my balls a bit as they slapped her curvy ass. In seconds, she was moaning and cumming again. Her orgasm seemed to go on forever, and her fingernails dug into my hips as she lost control of her body and clenched every muscle. Having her cumming on me like that was more than enough to put me over the edge, and I felt my own orgasm exploding between us. It was all I could do to support my weight and keep from collapsing on the floor beside the bed as I shot spurt after spurt into her quivering pussy. When we both came down from our orgasms, and I had to move or fall, she moaned softly, reached down between us and felt the cum leaking around my now-flaccid shaft, and smiled. "Mmm... thanks, baby, I love the feeling of cum in my pussy. Don't worry, I'm on the pill, and you know I'll never tell. She'd fucking kill us both!" She giggled and gave me that "we've got a dirty secret" smile. "Now, go home, unless you want to help with the laundry too." Fuck and run. That's a new one on me, I thought. I always thought women wanted to cuddle after sex. But then again, I thought women wanted hours of foreplay as well. Maybe this girl could teach me a few things. I could be a willing student.