Back in the days I (M26) lived with a roommate, who was out of town for the holidays.
So I had a friend of mine over, just to watch movies and relax together, nothing special. We had the kind of friendship, were we often flirted a bit but never seriously.

This afternoon we ended up cuddling, and I was being the little spoon, because it's just nice and cozy. As we watched a movie, I could feel something was different this day. She smelled better than normally, and something just got over me. I ended up being rock hard in my pj's, and trying to hide it the best I could.
I guess it took only a couple of minutes before she noticed, at first she seemed a little startled, but soon hugged me tighter and pressed her warm body against mine.

After a little cuddeling, she slowly moved her hand to my thigh and slowly started touching my thigh. This drove me absolutely wild, and she sensed this and whispered in my ear to relax, and let her caress me. So I let her touch my thigh. After a little, she started slowly feeling my, at this point throbbing, cock through my pants. I started to turn because I wanted to see her face to read the situation, to which she instructed me to keep still, since she couldn't see the screen when I move around. This continued for a minute or two, before she pulled my pants down just enough to flip out my dick.

She slowly started stroking and I swear it was heaven. She started dirty talking in my ear as she slowly stroked and teased me, still not allowed to move or anything. At last I moaned I was about to cum, to which she instructed me to imagine filling her up, and this was about just enough to make me blow.

To this day, we have talked about this and done a bunch of things together. So I have a lot of great memorise of this time, and a cum stain on my couch from the christmas in 2018.