Agree with this. It's been a month! OP with respect you are way too grown to be playing these games.

If you need to catfish people.. you might not be ready for a relationship and should maybe work on yourself and heal.

And at the end of the day the dude wanted to cheat so just move on. You don't owe him a big "ah ha! I caught you" because that's gonna make you look...insecure and crazy.

Just dump the dude and tell him he isn't for you. Which he's not. You deserve better but u also deserve to feel abit more secure about yourself and dating. A few weeks of seeing someone is way too short to be getting serious.

Next time maybe get to know someone's character better before jumping head first into sleeping together and dating. That way you don't waste your time and have more reassurance the dude actually wants to get to know you for you not just to hook up.