Im not sure what your whole story is, but you don't deserve this.
You have to ask yourself why he crossed the line you say you drew. Did you tell him what the consequences would be? Did you actually know what they would be yourself?
Do you think he's just pushing to see what you will take?
Or has he made a genuine effort to change? To help you? At this point it should be all about helping you heal if you are in R. He should be doing everything he can to make you feel safe and secure. Be totally transparent. You should have all passwords to everything. Know where he is, what he is doing, and who he is with at all times.
If you are going to be "moving forward" together at this point, he should be willing to carry you.
Having " a lot of fun" doesn't seem like much of a trade off for years of pain and emotional abuse.
And he most likely will lie again. If this has been going on this long and he's still getting away with it, why would he do anything else?
You are not the one destroying your family. He is. Do not blame yourself for his actions.