I get it about the lack of respect. I also get it about choosing to see him, I did so with mine for many years, and very likely still would do so if he were to contact me. I also get it about loving him.
I remember years ago saying to my H that I couldn't make him do anything, but that I could take myself out of a situation where I wasn't respected.
The one thing I don't do right now is contact him, about anything -- including anything to do with our now technically adult children, even things that parents "should" be in touch about. The times we have had contact before the last few years I did find myself enforcing boundaries, for lack of a better word -- not the kind we first think of, where we'd say we won't do a while they are doing b, but correcting things that are untrue with the basic words of "you know that's not true", that kind of thing. More specifically, saying no, you aren't, when he tried to say that he was always there as a father.
My reasons for not contacting are basically about respect; I wasn't being shown any, not even courtesy, so I realised that if there was anything he wanted from me about the children or anything else, it really was up to him. It was a pattern that had been repeated many times over the years; there was one specific incident where not even common courtesy was observed that made me sadly come to the conclusion that I would no longer be sending him anything to do with the children.
My children don't initiate contact with him; they respond with something very basic if he contacts them.
Were he to contact me I am sure I would be polite even in the face of monster, and if my past experience is any guide I would also be compassionate if he were to say something was wrong. I have no idea what might make him be in touch, however, so I will have to trust that I will know how to respond if that happens.