My wife's brother and his wife recently moved to our city. They stayed with us for a little more than a month while the construction on their new home was being completed.
About a week into their stay, I had gone into the office one morning as usual. As it happened, we had a power outage that morning due to a car accident - the vehicle plowed into the power pole in front of our building. Given we had no lights, A/C or electricity to run any of the computers, the management dismissed us all for the remainder of the day.
When I arrived back home, I found everyone gone, the house empty. I knew my brother-in-law was at work, and my wife had mentioned she needed to run errands, shop, and was going to have coffee with her friends; essentially out for the afternoon. I figured my sister-in-law had gone along with her.
It had been a while since I'd had any privacy, and I was admittedly horny with my attractive, young sister-in-law hanging around. She dressed comfortably, if not a little provocatively given the hot weather. She was typically in a light sundress, or wearing shorts with a thin tank top, braless. Her nipples always seemed erect, protruding through the thin fabric of her top, and from time to time I got a shot of her panties when she wore loose shorts.
I decided to change clothes, figuring I'd be more comfortable in athletic shorts and a t-shirt than the jeans and work-shirt I had on.
While changing, I thought about my hot young sister-in-law and imagined what she'd look like naked, showering or laying on a towel out by the pool. My cock tingled at the mental image, and the more I thought about her, the harder I got.
After I'd stripped out of my clothes, my erection was too nice to waste. I lay down on the bed, and began to stroke my cock and fondle my balls while thinking about my sister-in-law. I imagined making out with her, kissing her, pinching her hard little nipples between my fingertips, touching her velvet-soft skin.
I teased my cock-head, brushing it lightly with my fingers, rubbing that special spot underneath, slowly and lightly trying to make it last.
Laying on the bed, jacking, stroking, trying to bring myself right to the edge over and over, I lost track of time. I was thinking of my sister-in-law riding my cock, filling her petite frame with my thick dick, watching myself penetrate her wet pussy, cumming inside her.
I couldn't take it anymore, and I wanted to cum, to explode when suddenly I heard a bump, a noise like a door ajar. I raised up on the bed, my cock red, swollen and bobbing in the air and saw my hot little sister-in-law there in the doorway, her hand down her shorts. She made no move to leave, and said nothing, and instead just stood in the doorway, her hand busy between her legs.
My hardon was raging, and I felt myself blushing, flush with embarrassment yet filled with lust.
I moved to the edge of the bed, my cock stiff and throbbing and said "Do you like to watch? Would you like to see me cum?"
My sister-in-law nodded, remaining silent. I told her, "I've been laying here, thinking about you... did you know that?"
I kept stroking my cock as I watched her, eyes wide, lips pursed, her hand furiously busy down her shorts.
"You're so pretty, so sweet... I've been thinking about how it would be to have your sexy little mouth on my dick, your lips wrapped around my hard cock..."
She leaned against the door-frame, her legs trembling, wobbly and her eyes fixed on my pumping hand.
"I want to cum so bad! I want to squirt my hot cum all over you sweetie, I want to kiss your hot little pussy, lick my cum off of you..." I was stroking my cock faster and faster, knowing the edge was near.
She watched intently, and her breathing became loud, her face flushed as she frigged her pussy.
I couldn't help but imagine what it would be like to see her fingers run over her erect clit, to have the scent of her wet pussy fill my senses... "Do you want me to cum sweetie? Do you want to see it, to see my cock squirt all over?" With that, I lost it, spurting jet after jet of hot cum all over myself, the bed and the carpet.
My sister-in-law was moaning, one hand busy bringing herself off, the other a fingertip in between her lips, as if she was biting it to keep herself from screaming out as she gave herself release.
Both spend, we just looked at each other silently, me naked and semi-erect on the bed, her slumping against the door-frame, her hand still down her shorts.
After a few minutes, my sister-in-law backed slowly out of the doorway, and padded down the hall. I cleaned up, wondering what to think. At dinner that evening, we were both a little uncomfortable, self-conscious from the earlier event. She wouldn't look me in the eye, and was unusually quiet.
Several days later, she visited me while I was in the shower, and put on a little show for me - sitting on the toilet, fingering herself, and using a little pocket-rocket vibrator on her clit. I stood under the water, stroking myself into oblivion.
The remainder of the month was pure bliss, sexually charged, the two of us experimenting with masturbation and exhibitionism at every chance we got. I never made love to her, although I would've given my left nut so to speak to have had the invitation.
My brother and sister-in-law have since moved into their new home. I'm hoping for an opportunity to visit and see if we can put on a show for each other, sort of christen the new house. I miss the sexual energy and charge of having her around, and the "live show" release we got from each other as often as we could.