Well, an update from this:
https://bpdfamily.com/message_board/index.php?topic=3062208.0Yes, he cheated on me with our mutual friend/ workmate.
Yes, he lied to my face about who he had slept with and about conversations they had afterwards.
Yes, he/ they concealed this from me the next couple months, while we still worked closely together.
Yes, it is the second time he has done this.
I say firstly:

, and secondly, lmao.
But thirdly: there were always signs he lacked integrity. And honestly, I knew this. I learned of actions he undertook which lacked integrity before our relationship, and now after. There were also things that contradicted our values that he would have done while we were together, but he told me he didn't, because I was guiding him. But also - because he was 'afraid of me'.
Fear and being guided by another person are not a basis for integrity. They can only come from oneself.
I knew this, or should have known. I chose not to look, or to construct a story where I would be some kind of saviour or hero who would teach him to be different. And wasn't that my own responsibility, a wilful blindness from my own needs and ego?
I'm not sure why I still find it hard to detach. Honestly, I knew what I had with this person was not the 'great love' I had believed in the beginning. There were too many discrepancies between what he said and what turned out to be actual. And that caused great instability in our relationship and in my sense of what was going on.
I don't want to be with this person. I can't live with manipulations and lies, or even with the exhaustion of being his daily keeper and caretaker. But I feel great grief for the shared life and shared values we were building (I thought we were building) together.
There are some steps I am taking where I am moving towards goals and a future which I thought were shared goals - things he said he deeply, desperately wanted. But I don't know if they were really his goals, or my mirrored goals. But in the end, I'm moving towards them. And it turns out I was by myself in this all along.