Cheating thoughts?

So I went to this college party last night, and my friend was flirting so much with this girl. She's tall, pretty, gorgeous.

After about 2 hours in I saw them kissing and making out but I didn't think much about it. This was around 10-11 pm.

I continued partying with my other friends without worrying about my friend. Then around 1am I saw this girl came out of the bedroom with my friend and she was crying so much.

Obviously my instant thought was my friend did something bad to her.

Later I found out that she was crying because she felt guilty that she cheated on her boyfriend and had sex with my friend. I had no idea this girl was taken.

Idk but to me she was playing the victim and my friend looked very guilty about it. Everyone else was trying to reassure her that she's gonna be fine etc, while everyone was looking at my friend like he was the one in the wrong.

But to me, she could've stopped everything from happening hours before. I saw them flirting for the longest time but I didn't feel bad for her. I felt bad for her boyfriend, though. I just dont understand why people always take the girls side