“I knew it! I could tell something wasn’t right, so I checked your phone to prove myself wrong...but I was right, you lying, cheating, sack of shit!” If he tries to gaslight you like you’re the bad guy, reiterate that he’s a lying, cheating sack of shit. That’s, like, at least twice as bad as being a snoop. Maybe even more.

Just leave. It's not worth it, no matter who's at fault, although it seems to definitly be all his in this case. If you live together and you own the home, change the locks and put his stuff on the curb with a note that briefly tells him to have a nice life with his cheetos. If he owns the home, spend a few days packing everything you own and leave without a word. If you both own the home, you're going to have to just come out and say it, or, if you prefer, just say you don't love him anymore and want to separate your life from him. If you don't live together, it's simple. Stop responding after an intitial "It's over".

Leave him. He hurt you. To the core. He does not respect you. Leave him. It will be hard. But your own self worth and self love is worth more. Just let him know what you did wasn’t right. But you had your suspicions. And you were proven to be correct in his unfaithfulness and feelings that something was off. Don’t let him deflect and blame you or any of your actions. He is solely responsible for his own actions. Leave him. Leave him.

Shame on you for invading his privacy! Let him go and tell him you're not good enough for him. You can always become one of his side pieces if you're that into him.

I mean, you can leave a crappy relationship for any reason - And him being a cheating scumbag is certainly enough of a reason. You don't have to have a perfectly unassailable justification for doing it. Was snooping not great? Sure. But does it mean you're now obligated to continue be stuck in a terrible relationship with someone who's betrayed your trust deeply, and exposed you to all kinds of risks? Absolutely not! Let him and anyone else who complains about how you found out complain - It doesn't make him any more moral, or you any less justified for leaving.

Just break up, you don’t need to tell him why or how you got the info. Tell him it’s not working for you.

Who cares how you confront him? Y'all need to break up anyway, obviously. "Hey I went through your phone and know you're cheating, so we're done" is all that needs to be said. Work on your need to go into peoples' personal belongings on your own time; don't even involve him.

Seriously? You think that's an even an issue? He's a cheater and you need to dump him. Doesn't matter how you found out.

The truth of the matter is you don’t need an excuse or reason to break up with someone. If you don’t trust boyfriend just end it.