My first detective had a close relationship with her, which she ultimately maintained. She was real pissed that their lies had gotten innocent people killed and she took every opportunity to throw that in Rebecca (and Unit Bravo)'s faces, but while she may need longer to forgive Rebecca she does love her mother
Keiji, on the other hand, is the complete opposite. He resents Rebecca because she was never there during his childhood, and the reveal didn’t make anything better. He didn’t know how the fuck to deal with the fact that vampires are real what the fuuuuck so he just kinda… didn’t, and instead focused on his anger at being betrayed by Rebecca yet again. He didn’t trust her before he found out she lied to him and he doesn’t trust her now. She might pretend to care when people are watching but he doesn’t want to let himself start to think that it might last (because once you get emotionally attached to people there’s the possibility of getting ~hurt~ and this poor boy and his shitty emotional stability can’t handle that)
Lastly, Jay. He had an alright relationship with his mother, not terribly close but Jay’s not the type to express overt affection anyway. He knows his mom cares about him and he cares about her and that’s enough, even if her never being there meant he’s grown up learning not to rely on her. Post-reveal Jay… needed some time to let things sink in, and honestly one of his first real reactions was ‘thank fuck I’m now in the know so I can actually find the killer that’s threatening my town’. His relationship with Rebecca is mostly unchanged. He now knows why Rebecca was always gone, but knowing doesn’t give him back any of the time they lost. It doesn’t mean he’s any closer to her than he was and it also doesn’t mean he wants to be closer. He’s fine with things as they are, thank you
and @blackrising, I’d like to second all you’ve said. Keiji, the guy I’m “romancing” M with, wouldn’t be particularly hurt by M being cold/stand-offish about it cause, well, he isn’t in it for the romance either. Not until the both of them start tripping head-first into feelings and there’s gonna be some choice denial about that, that is.