Bitter ex!

So I wrote here before telling you guys how my ex cheated on me.. and I left him. ... for the past few weeks I've been dating this amazing guy.. like he knows about my past relationship, how scared I am of getting hurt again.. and he just keeps sweeping me off my feet! I feel butterflies we talk all night on the phone.. he has 2 kids I have 2 kids we both work weekdays & spend our weekends together.. its such a good feeling... BUT recently... my ex called me.. trying to "talk" ... should I hear him out? I told him I'm seeing someone .. but he wont stop trying... maybe I'll block him!