Ex boyfriend ?!

My ex boyfriend of 4 years recently added me back onto social media and i had him blocked . He made whole new accounts to try to add me. Keep in mind he cheated on me and got engaged to this girl, has a kid with her & is now trying to talk to me again.. I have a boyfriend of almost 2 years now. What do i do? Just block the dude all over again even if he continues to make new accounts? I feel bad for his Fiancée! But I won’t say anything cause she hates me so much. She hates me so much she sent me a video of them..yeah! :) lmao they both need the help .