Caught s/o

So I caught my so texting an ex gf. She text “have a good day” and he responded “thank you, you too.” Harmless right? Well not when this beeee used to call him all the time when she was in a bad situation, for example, getting pulled over and her car taken away. She would run to him. I told him he had no business talking to her,especially because she’s an ex. He swore he stopped and blocked her #. Nope, he only changed her name on his phone. I was ready to leave, We talked and he promised he wouldn’t talk to her again. I don’t believe him but I was willing to try. This happened Wednesday night.

He gave me access to his bank account in case I ever needed it since we live together. I’ve never used it and never checked his account. He makes great money and he told me he didn’t have money right now to buy tickets to a baseball game I want to go see for my bday next month. I know what his bills are and there’s no way. So yes, I checked his account. Not my proudest moment. Mind you, he gave me access to it. Well, I found transactions from Apple Pay to that exes #, like 15 of them. And they weren’t small. They were between $50-200. Like wtf!!!! The most recent was Wednesday afternoon for $80!!!

But I can’t just wake him up right now. We’re at my parents visiting for the weekend and I am not about to make a scene in front of them.

My question is, how do I go about it?

Is it worth staying after this?

Am I exaggerating?

What should I do???