This happend while at uni. My friend group all went to my mates student flat for a party. My GF was down at the time so she came along. There were 7 of us in total.

Anyway we all had drinks, danced and played games and then it was time to crash. My mate said he gets the bed as it's his, my gf gets the bed also and I can squeeze in since she wanted me there.

The other 4 guys had to cramm together on the floor and sleep. Safe to say the room was boiling and we all said we would keep out clothes on. Sleeping in jeans is not fun.

My gf had a skirt on and tights. So after some banter from everyone. People started to crash. I started to doze when I heard and felt it.

I heard my gf gasp and felt the bed shift slightly. She was lying facing me with her ass towards my friend.

Well it didn't take me long to figure out they were fucking. I was going to stop it but I noticed my gf was moving her hips into him. She tried to keep quiet and he continued his slow deep thrusts.

I then herd him cum into my gf and she quivered. I'm guessing she came also.

They then fell asleep and I was left wondering what to say or do. I fell asleep also.

Then before leaving I noticed her tights ripped and asked what happened. She froze and said it must have happened while sleeping. We left shortly afterwards and I started to plan my revenge