Found out new bf wasn’t honest about hooking up with other girls

So I recently got into a relationship with a guy I was previously hooking up with for over a year. We both said it was casual and I even told him he was free to see other people as well. Thing is, he told me he wasn’t and lied about it, was sneaky. Turns out he was seeing other people for the first 8 months or so. I believed him the entire time. Once we decided to date each other exclusively, he stopped. So 8 months now.

I only know this because of snooping (another issue I know- please don’t comment on this) so he doesn’t know I know. Do I even bring this up considering he technically never cheated. I just don’t appreciate the lying/going behind my back.