I’m confused if it’s just Lust or I should move on

I have been with my bf for 12 years . I love him but through these years it’s been time when he don’t come in and he blame it on he was drunk and passed out over his friends. Anyway I recently start going out and I been talking to other men... So after a couple months I start talking to this other man who had a crush on me and I had sex with him ..I know it’s wrong but I love my bf but I love this other man sex.. I don’t know what to do.