Is he a cheater??

Lex

So the guy I’m with now we’ve been dating for three months. He offered to give me his passwords for social media. So me being the nosy person I️ am I️ get on his Facebook messenger. He works 5 hours assay and is gone for two weeks at a time then comes home for a week. I️ click on the messages between him and his mom and I️ start reading past messages. His ex girlfriend and him were together for two years off and on. When I️ started reading the messages I️ found out that he had hung out with this girl that’s considered a skank in my town while he was dating his ex, and his mom asked him about I️t. So should I️ bring this up or let I️t be the past?