There was a girl who was flirting with me but she ended up hooking up with my friend at the end of the night. They're together now but I'm thinking of trying to hook up with her now.
Why would you wan;t to be involved in a messy situation like this?
I'm disappointed with my friend for doing this to me. He damaged our friendship forever.
Being upset at your friend for "stealing" the girl out from under you sucks but it's not worth the effort to mess with their relationship, especially if he already ruined your friendship. You should just move on because she was probably not a relationship worth pursuing. Getting involved with people who are already involved with someone else will just make matters even more complicated and messy.
I'm going to hook up with her and let them know that I will hurt them both.
Although that revenge might fee good at first, in the long run, I think that you would feel more regret than joy.