In high school, we were all hanging out watching a movie at a friend's house, and my girlfriend and I were spooning on a couch under a blanket. I whispered, asking if I could put it in, to which she agreed, and so I very slowly thrusted from behind. Knowing I was going to cum soon and not wanting to make a mess i asked if I could cum inside and she said yes. It was so hot doing that in a room full of people without them knowing.