My best sexual experience was with my ex-wife before we were married. We were both virgins, had decided to wait to have intercourse, but we did something very close because it was so hard to wait.
While on a camping trip we shared a tent with friends of ours. The tent was smaller than we had all thought and so we were all crammed in. They fell asleep fast and so we laid next to each other in bed and I held her close and she had her back to me.
Both of us feeling horny, I put my cock between her legs just on the surface of her pussy. I pushed in and out as she held her legs together and I slid across the surface. The most amazing thing about it was how close we were to them at that moment, almost touching them and I think she placed her leg on the other couple to make it even more risky which blew my mind. It was one of the best orgasms I had ever had and I had to cover her mouth aggressively when she came so she wouldn't wake them.