I like my friend's boyfriend
How would your friend feel if you dated your their boyfriend?
I hope that we can still be friends after that, I don't see a problem.
The problem would be that she would be upset. You shouldn't pursue your friends boyfriend. It's called cheating.
He said he's open minded. I'm just gonna tell her we made out and see what she says. I think it's being honest at least.
This is not going to be fine with her and you know that. You are only seeing it from your own point of view which is somewhat selfish. Think about her and not just your own wants, one day it might come back to you in the end too.