Yes, snooping was a bad idea. But does that mean what he was doing was okay? Shouldn't he still apologize and acknowledge what he did was wrong?
Most Helpful Guy
If it has reached the point of snooping AND finding out he's texting other girls then there's a fork in the road.
You need to set the record straight and sit down with him, tell him you're serious and say that you're no way anywhere near happy with his behaviour.
You need to tell him you feel uncomfortable with it and he needs to stop. You found out about it as you were curious and maybe suspicious... you're not an idiot.
If he projects the problem back onto you then perhaps you need to find someone else or be single for a while. As you might end up that way anyway if he decided to follow through with anything (been there and got walked over and cheated on... don't believe the lies. Be YOUR own person. Own it)