Sorry for the length. This is my first post too.

So my female friend was having a little thing at a hotel. We were suppose to spend the night over and she invited a whole bunch of us. I invited my girlfriend too, so she could finally meet my friends.
Fastforward.. we are in the hotel and we put the music on. We should've been dancing but what we were doing was a mix of dry humping and sex. It was cleverly planned so everyone had a partner. I got really turned on watching everyone getting crazy. Unfortunately everyone went to bed around 3. even my girlfriend. The only thing that was going through my mind at this point was how i was going to make it look like a mistake when i woke her up.
At this point we were sharing a section of the floor secluded from the other 10 people. I quietly laid beside her in a spooning position and see if i was gonna get a reaction. Nothing. My girlfriend has quite a fat ass, so it didnt really take much for me to get a massive hard-on.
i started moving my waist and still no reaction. At this point, i was getting frustrated and decided to take a walk. maybe the opening of the hotel door would wake her up. Im walking down 42nd st in NY as i received a text "where are you" IT WORKED!! I told her that i was taking a walk because i couldn't sleep. I told her to come take a walk with me. She said she didn't want to wake anyone up so i decided to go back and try again. I got in the room and sat beside her and she immediately gave me a kiss. She then whispered in my ears "I am so fucking horny. Fuck me!!". All of a sudden my stupidity kicked in and i became rational and asked "here in front of everyone". "Yes and now" she replied.
my stupidity escaped and we covered ourselves again. We went back into the spooning position and we put each others pants down. She arched her ass back and i slid my cock into her pussy. It went in fairly easy seeing as she was already leaking. I took my fingers and circled my penis so i could get a taste of her cum. Then i started pumping. She squealed and quickly put her hands over her mouth. I pumped harder and made her loose control. She turned her face to the side and whispered that she was cumin. I maintained pace and all of a sudden a shiver from her and she came wetting my cock even more. I continued to pump and then pulled her hair she shouted and covered her mouth again. We heard stirring in the back ground and one of the girls got up to the bathroom. I didnt stop. "You're so naughty" she says. "Your pussy does that to me" i replied. a minute later a guy got up to join the girl in the bathroom. Thinking of the possibility of what they were doing turned me on even more and i pumped faster. She came again. I layed her down flat on her stomach and i layed on her back. I squeezed my fingers through her body to find her clit. with some luck i found it and rubbed it as i pumped her. "im cumin, im cumin" she was breathing the hardest all night and that made me build up. As i pumped harder and harder she came and i came simultaneously. It was heaven and tiring. I layed back and put my pants up as she did too. "Thank you" she said. "No, thank you" i replied. it was awesome.
for anyone who cares, the two people who were in the bathroom came out 10 miniutes after we finished.