Girlfriend and I During Sleepover

When I was 18 I met a woman who would really help me explore sexuality. We ended up dating for a couple years and had sex almost daily, usually multiple times. We used to see how many different places we could get away with "playing". She was around 5'5", long brown hair just down past her shoulders, modest breasts, naturally soft tan skin, a tight round ass, and always shaved clean. I could tell the days she shaved because she would be hornier than usual. One night, we had a group of friends over for some movies and drinking. My room was in the basement and was very large. I had a bed and a couch in the room. In the morning, 2 female friends were on the bed, another female and male friend were on the couch and my GF and I were on the floor. My GF had an insatiable sexual appetite. I woke to her cuddling up to me and slowly stroking my cock through my shorts. Once she could tell I was awake she began kissing me deeply and stroking faster. Once I was rock hard, she slid down my shorts and my thick hard cock sprang to life. She proceeded to climb on top of me and straddle me and I realized she was only wearing a loose top and a small thong. She started sliding her hips back and forth, using hew pussy now to stroke my cock. I could feel her panties were soaking wet which sent electricity shooting through my body. I looked around to see if any of my friends were awake but as far as I could tell they were still asleep, which was hard to believe due to my GF's moaning. I told her I wanted to be inside of her but she said I had to wait, she just wanted to make me cum while our friends ares right next to us. So I reached one hand down and squeezed her ass and the other up her shirt to caress her perfect breasts. She kissed me deeply sliding her tongue in my mouth and started grinding her hips faster and faster. I whispered in her ear I was about to cum and I could feel my cock throbbing on the edge of orgasm. She told me she wanted to feel my hot cum on her stomach and panties. So pressed her stomach up against mine and pressed her pussy and wet panties firmly against my cock as I started to shoot several large hot streams of cum all over us. She grabbed a towel that was next to us and cleaned me up and proceeded to put her sweat pants on and head to the bath room. When she came back she handed me her wet panties and told me she just came twice all over them while pleasuring herself in the bathroom and to use them as "Motivation" later, and I did many times. As far as I know, my friends were unaware of what happened right in front of them.