Am I wrong for breaking up with him because he talked to his ex?

So my now ex talked to his ex girlfriend. He cheated on me years ago and we split and during that time he got with someone else for a short while. So like 2 years ago we got back together and just like how he treated me when his ex told him to block me. I told him not to talk to any exes after he cheated. So he talked to her and I got mad and told him I couldn't trust him. He thinks I'm being unfair but I feel it's fair.

Am I wrong for breaking up with him because he talked to his ex?
Post Opinion