Dating someone new do I tell my ex boyfriend?

I have an issue I need some advice on . I started dating someone new. I am going to see him for New Years. I am wondering if I should tell my ex since we talk regularly and still have mutual friends. I don't want him to find out another way. We have tried to make it work before but I don't see it happening . We have a lot to fix and forgive. Not to mention we live on different coasts. I know he still loves me so it makes it hard. We were together on and off for 3 years. But I think I am ready to move on. I still care about him so I don't want to hurt him. My question is when or how do I tell him I am seeing someone ? Thanks