I agree. Your relationship with your current bf is doomed either way. if you tell him, i doubt he will never feel the same way about you, and to top that off he will probably try to get back at you, even if he doesnt do it right now, even if he doesnt mean to. if you dont tell him then its all built on a lie. i know if my bf cheated on me i would rather know and end it than go on thinking everything is great. as for your situation with your ex, you need to cut off all contact with him. obviously you guys arent meant to be or he wouldnt be your ex, he cheated on you anyway. when he was off fucking some other girl, do you think he was thinking you and how you would feel if you knew??? NO. i used to go bac to my ex all the time and it would just make me feel like shit after. when you think about how much you still care about him remember to also think about all the times he hurt you. you should just move on, make new memories, better ones... goodluck.