my gf is still in the partying faze she is very sexual all the time have intercepted message between her and coworker talking about going to clubs her coworker is married but likes to hook up with black men they were out partying appears my gf is messing around with some black guy now. she says its just fun would never be with him long term and wants to marry me. I pretend not to know as much as i do. But am concerned dont want to get hurt but also concerned for her. Would it be appropriate to negotiate boundaries