This happened two weeks ago.
Two weeks ago my step-daughter Cece, 19-years-old, and I were home alone during the morning hours since my wife works mornings, and I work nights, and Cece was on school vacation.
One night, about a year ago, I arrived home around 11:00pm. and every member of the house were sleeping, and as I walked through the hallway, Cece has the first bedroom, I heard a soft noise coming from her bedroom and her door was half way open. Since I didn't turn on the hallway light, I went to look and see what was going on and she was humping a pillow face down and covered with a blanket.
Well, two weeks ago when we were alone, she walked into my bedroom to take something from my wife's make-up box and I pretended I was sleeping. I was uncovered just with my underwear on, face up and with my eyes closed. I felt her getting close to me and as I opened my eyes barely enough, so she wouldn't notice I was awake, I saw her looking at my erect penis covered with my underwear. Then she reached out to touch it, like barely caressing it, and then slowly pulled just the head from the top of my underwear.
I saw her looking at it and looking at my eyes, I guess to make sure I was sleeping, and she kept on caressing it and I felt that my hard penis was starting to drip pre-cum and she was rubbing it around the head. I started to cum and she moved her hand away as I just moaned but didn't open my eyes. Then she walked away trying not to make too much noise. Up to this day I think she really thinks I don't know what happened and I don't know if I should tell her all about it or just keep it to myself, but that was a very pleasurable experience.