I (30m) was probably 20 at the time. My girlfriend at the time was 19. She brought her friend (19f) over to watch a movie with us one time. I can’t really remember what the movie was and you will see why in this confession.
We were all lounging on the couch, we had a big L shaped sectional. My gf and I had a really big blanket so we were all sharing with plenty of room in between us. During the movie my gf’s friend went to use the bathroom. I glanced down and saw she had on ankle socks. I have a thing for pretty feet and socks so I started to get turned on. I tried to focus on the movie again.
When she came back she caught me looking, I’m pretty sure. About 20 minutes later I felt her foot caressing my leg under the blanket. I started to get red and nervous because my gf was right next to me. She moved her foot up my thigh teasing me until she felt my bulge. She then wiggled her toes on it and stopped.