It's funny... .he even bought Boundaries by Cloud and Townsend.
Might this suggest that he feels like he is being attacked in some way? And, is actively looking for solutions in which to deal with how he feels he is being treated? Generally, that is.!
The only way I would stay with him is if he took responsibility for his actions, went completely no contact with his cult-like abusive/enmeshed family, acknowledged his dishonesty and delusions, and finally... .felt remorse for his actions and apologized to me for everything.
This would be a big ask for someone who is looking to learn about boundary setting.
Your statement implies that you are giving him an ultimatum (which seldom, if ever, work). He has to own up to all these things and take on the idea that he is a thoroughly unpleasant person (further attack). You are asking him to cut off all contact with his family (who, it seems to you, are toxic too ... more attack). To be with you, you are demanding that he show remorse ... which is going to further reduce his feelings of self-worth because he will feel that he has to back down (making you better than he ... in his eyes) ... and this may lead him to feel that you consider him to be beneath you.
My point is this...
You are asking someone that displays defiance as a defence mechanism, in all manner of ways, to defer to people who he may feel are threatening, extremely critical of him and hypocritical. I agree, it does all seem a little twisted unless you can truly put yourself in that person's shoe's and see things (without prejudice) from a very different perspective from your own 'personal' one.
Consider for a moment that his family of origin, or an influential member of his FOO, has treated him in this way for much of his life. If this is the case ... can you see how he might feel that you're being just like that person?
He might feel that it is easier for him to just go and try again with someone else (since he is not good enough for you). Which, quite naturally, would lead you to think that he discarded you in a most horrible way, furthering your idea that he is uncaring and you are better off without him, and further fuelling his idea that you think he isn't equal to you.
Not that I'm condoning his behaviour (which is awful and hurtful) ... what I'm trying to point to is ... whilst his actions are hurtful and rejecting ... your words, in reaction to his actions (to him) are equally as hurtful and rejecting. Does that make any sense? Perhaps, perhaps not.
These are just my thoughts surrounding these dynamics RoboBird and not, in any way, backed up by empirical study. However, when we say that we try to see things from other people's points of view ... are we really being honest with ourselves about doing so? And, are we truly tapping into our ability to make use of the ability to truly and unconditionally empathise?
I am wondering why you started this thread with "Trigger Warning" and what that might have meant at the time of writing. I'm wondering if you intuitively expected a reply which would trigger some frustration.
I hope not.
We all want our share of love and happiness, a sense of purpose, and to feel validated and fulfilled. I believe we should try to make efforts to see things from as many view points as we can ... prior to making judgements (which is a natural tool of humanity). And, I feel it is right to maintain our personal values and walk away from those, with very different values, who we feel are detriment and non-conducive to emotional security, fair play and peaceful living.
All the best to us all as we try, in our own ways, to unravel all of this.