While I was Masturbating, my brother fucked one of my friends (18F).

During the summer between my senior year of high school and my first year of college, my brother (20M) kept trying to hook up with one of my friends (18F). I offered to help him and invited her to the house a few times. He was able to get her number in the end. After that, they went out a few times and then came over to our house to hang out as a couple. It was pretty clear that I had to leave when my brother told me she was coming over.

Until one night.

Someone from my team and my brother were sitting on the couch together when I walked in from spending the day with someone else from my team. They asked me to hang out with them and watch a movie, which we did. But the movie had some hot sex scenes that made it clear that those two were going in the right way for the night. After the movie, they said they were going to bed, even though it was almost 9 o'clock at night. I laughed and said okay, knowing it wasn't true.

I decided it was time to go to bed after they left (I'm a grandmother, I really wanted to sleep).

My room is right next to my brother's, and his bed is against the wall next to mine. My bed is on the wall facing his room. There aren't many walls, so you can hear everything. The style is awful, but it is what it is.

As soon as I was dressed and in bed, I turned over to try to fall asleep, but I heard noise and movement on the other side of the wall. Fuck.