So I will assume you are eluding to the fact that it will continue as such unless I cut all the strings and have No Contact?

I still say it is sad that he felt he needed to have more than what his GF was giving him. That should have been more than enough.

Greed will get you every time.

Who knows what he really wanted, but his actions clearly demontrate that he's a cheater and a liar. So if that's not what you want, then leave him in the past and find someone else who is more compatible with you.

You can either keep dwelling on this guy or you can spend you time finding and being with someone who is actually special to you.

I would say, don't waste anymore time on someone who isn't worth your time and energy.

As for your initial question: "how do deal with this?". Don't deal with it. There's nothing to deal with as it's a non issue. Leave him in the past and move on to bigger and better things in life.

What he is likely doing is, telling the live-in girlfriend, that YOU pursued him, and you were he aggressor, and you threatened to tell her everything if he didn't keep seeing you. You blackmailed him! You made him do things he didn't want to do!

He is blaming this on you, as evidenced by the angry phone call from him. He is covering his lying rear end, because he got caught having an affair with you.

That both you, and his significant other did not know each other, was by design, not by accident.

However, now that you know, why on earth would you give him a second thought.

Let her have him. He's has the moral compass of a garter snake, and mixing it up with him in any way, shape, or form, is a really bad idea.