<human>: This is my first time posting here so forgive me if I'm breaking any rules or if it's the wrong place.

A couple days ago I hooked up with one of my good friends and I've been feeling really bad about it. She is sort of dating this other guy, not officially boyfriend and girlfriend or anything but she's definitely interested in him. 

We were laying in bed together talking and she told me it was sort of a "last hurrah" before she got into a serious relationship. After that night I've felt a bit more attached to her but I don't see myself having a chance with her as she likes this other guy. It just feels really shitty to not be able to tell her how I feel or act on my feelings. 

I'd much rather just remain friends than ruin anything by trying to make it something more. I don't feel used or anything like that, just a bit disappointed in myself that I did that because I am one to get attached easily (which I'm working on) yet I knew she was seeing someone. If anyone has any advice, maybe a different viewpoint on the subject or just any thoughts at all please share.

Can you condense the text into three sentences or less?
<bot>: Hooked up with friend who is beginning to date someone else. Now feel bummed that I can't tell her how I feel as I probably have no chance with her. Would appreciate any advice or help.