my boyfriend cheated on me with his girl best friend?
Too late for that, when he crossed the line with her, there would be no turning back. Either he needs to end the friendship or the relationship, he can no longer have both and he needs to make a decision just be prepared, if she really is his best friend, he will probably choose her. I really think you’re better off moving on, if he’s cheating he doesn’t care enough about you, that’s business alone no matter who he was with tells you that.
My boyfriend cheated on me with his “best friend”. He still wants to be with me and hang out with her too. What do I do?
Don’t even think about this. He has no regrets because he just wants to have his cake and eat it. Get rid of this and go do your own thing and find someone with better manners.