<human>: Can you give me the gist of the text in a nutshell?

Been with my boyfriend m (19) for 4 years.

 Three girlfriends and I went to a halloween party. It was really packed. I planned on sleeping in a small room with one other girlfriend. Went to sleep on a treadmill that was inside the room. I wake up maybe an hour later (not too sure of the time exactly) to my girlfriend having sex with some guy on the floor about a body length away from me. I didn't know what to do to be honest. I should have just got up and left but I had never been in a situation like this before. So I just turned over and tried to get back to sleep. I couldn't and maybe about 5-10 minutes later they finished and I was able to fall asleep. I'm not sure if what I did was really bad (not getting up and leaving). And being so close to them while they were having sex makes me uncomfortable and feeling guilty. They were both underneath sheets when I woke up and saw what they were doing so I couldn't have seen anything. And it's not like they were in the same bed as me..but should I feel badly for this?
<bot>: Woke up to my friend having sex with some guy on the floor a couple feet away from me. Feeling guilty for not leaving right away. Feel uncomfortable that they were that close to me.