My ex boyfriend cheated on me. he is now dating a girl. on two separate occasions he has tried sleeping with me and I've talked to other girls he's tried sleeping with. I feel like I need to tell his current girlfriend but me and him still communicate because I'm a co owner of his car. I'm worried she will tell him what i said and he will become upset with me and hurt me(emotionally and mentally) but I'm so scared she will be heart broken what do I do