My bf (24M), is going to a concert with his cheater friend (24M). Advice?

Hes going to a concert with a friend he works with. We last went to a concert together which was also my first time meeting my bfs friend. Prior to the concert tho my bf did mention to me that his friend said that he was going to "test me" and see if i was loyal. I was like wtf does that mean. So he elaborated and said that his friend said he was going to try and hit on me during the concert and also message me after and if i 'fell for it' he was going to tell my bf if i was being unfaithful.

Which to me was odd because wtf. I dont know this fucking man and ive never been unfaithful the 4 years being together. My boyfriend did get mad at him and told him if he even tried to hit on me, hed fight him. Anyways that whole situation was so weird to me and it just threw me off with his friend. Mind you im not the type of gf to tell my bf who to hang with and who not to because hes a grown ass man and should know. Not saying I wont tell him but were grown and you should just know.

Anyways fast foward, theyre going to a concert and my bf invited me i said no i didnt wanna go. He then tells me that his friend wanted to invite girlS to the concert with them but my bf said no. He also told me that hes unfaithful to his wife and is always with different girls ALL NIGHT before going back home to his wife. This doesnt sit right with me because lets be real, if hes a cheater and married and inviting girls to go to a concert with them theres a chance hed probably try and influence my bf to cheat as well.

My bf assures me nothing will happen and if he does invite girls hes going to leave him alone with them. But theres going to be alcohol.. and all it takes is peer pressure. So should i make him cut him off? Wait it out? idk whatttttt