Yet he's acting like nothing in the past happened at times. He wants to be my friend as we divorce.
Parents are currently divorcing, my mom came to visit on valentines day (we had a get together with dad [quite possibly BPD], mom works out of town) and dad went straight for a kiss, got shut down.
Days later they went to get some paperwork done for her car (still registered under my dad btw) and were all smiles and funny stories, up to and including her saying she would have wanted more kids with him.
Dad is overly attentive to my grandma (mom's mom) when she visits
Mom also goes to visit dad's sister and her extended family, everyone knows about the divorce but still feel awkward about how to handle it (do they act like friends? family?)
All that after a long history of rages, smear campaigns on both sides, financial issues, family disputes and a few failed marriage counseling visits (dad convinced the therapist he was the victim, he wasn't really)
Point is, current emotion tints past memories. My mom is impulsive but not likely BPD, so its not just "a BPD thing". She was the one to initiate the divorce, and yet keeps acting in many ways like the divorce filing never happened, while at the same time she keeps pursuing it. Dad also tries to "act like a husband" even though he's been adamant about not taking her back and giving her anything in a settlement (he's convinced he did nothing wrong!)
I guess it's a way of dealing with the guilt on his side
I don't think they really have such devious ulterior motives.
I don't think my dad wanted to kiss mom out of a sense of "not wanting to give her anything" as he says re. the divorce, or about guilt from past mistreatment, and I'm not sure mom just "casually" mentioned wanting more kids with him if she had been able to (medical issue, long story) out of guilt of divorcing him and wanting him to "suffer through the divorce same as she did the marriage" (she said that to me once), this is a weird thing they're going through and I think they truly believe what they are doing at the moment is the "normal and correct" thing to do.
At least you know better, enough to see the

from a distance