HELP! Cheater Alert?

There's a guy that I've been entertaining for a while now. He just broke the news that he's been in a relationship for the past 5 years with a woman and is no longer happy. We're very open with one another, we were friends before we became intimate. He's told me he loves her but just doesn't think she's the one anymore. What do I do... We're both catching feelings. But I would hate for my bf to cheat on me. This isn't me at all! HELP 😩