Getting seen by sister in law.
My wife's sister and brother in law were visiting from out of state. Having just relocated from across the country, we were staying in a big apartment in a fun new town, and they were staying a week to see the sights and help us get settled.
Traci is my wife's youngest sister, and she's very cute, thin and blonde with a fun personality. Though she was many years younger than me, I knew she was attracted to me, as I'd caught her taking peeks at me on several occasions in the past.
I'd stayed up late working the night before, and I'd slept in a little. Our bedroom was just in from the dining area. It was a beautiful morning, and the light was streaming in from the large windows in the main living area, where Traci and my wife were seated, chatting. The bedroom door was open, but the girls were just out of my view around the corner of the doorway. But just barely. I knew from where she was sitting that Traci could see the lower half of my body.
As usual upon just waking up, I was hard, and I mean really hard. It was kind of thrill to know that I could be seen by my wife's sister without her knowing that I knew she was seeing me. With this in mind, I lowered the covers some and began to stroke my cock through my tented sleeping shorts. I assumed that Traci was looking, but I didn't really know. Getting bolder, I slipped my cock out of my shorts and began to lightly stroke, listening to the conversation in the background.
The first sign that Traci was watching was her increasing inability to hold a conversation. She sounded distracted. I stroked my good sized, cut erection more intently now, totally turned on by the situation.
Just then I noticed something I hadn't before, the big glass doors just off to the other side of the bedroom door. The way the sun was hitting them, they were acting as an excellent mirror. In them I could see Traci quite clearly and, I realized, she could see me as well. She had turned in her chair towards the bedroom and was clearly taking every chance she could to watch my reflection as I stroked myself quietly but quite in the open.
I'm not sure if she realized that I could see her watching me, but it didn't matter either way. I was on the verge. As she looked on, sneaking peeks that were probably too long (I wonder what my wife was thinking), I was getting closer. Finally, as my sister-in-law looked on, I came, shooting three big streams up in the air and onto my stomach. I got up and went to the bathroom, located in our bedroom, and cleaned up a little.
When I emerged, from the bedroom I said good morning to Traci and my wife and detected a blush still on Traci's cheeks and I was secretly thrilled to have provided it.