timelines are hard to pin down definitively, but I feel like at the point of the magnae accessio lucien/abelard has been long since established. they've been together for more than a full year, and had already started being serious about it a long while ago atp
meanwhile with kibellah and solomorne and yrliet, his relationships were much fresher and more undefined still like he has been sleeping with kibellah and solomorne, sure, but with kibellah it wasn't really that clear yet if it would turn into a proper commited relationship, or just some physical fun, and with the whole "i am your living weapon" thing he hadn't even really decided how much he cares about her as a person vs how much he just wants to foster her as a tool yet (yea, asshole moment, not his first and won't be the last) and with sol it was fun playing pretend at courting and dating for lucien, but he had already been suspecting something is off about the whole thing from the start (totally not because he is paranoid about emotional commitment as a whole, no sir), so he never fully commited to the emotional part of that relationship either meanwhile yrliet... well, yrliet is yrliet. i feel like he didn't even realize they were "dating" because the whole sexless spiritual connection thing is such an incredibly foreign relationship concept to him, and they haven't even started meditating together yet, so he probably didn't even consider what they had to be anything close to a partnership/entanglement/affair/whatever at that point in time
anyway, that's why abelard was the first and only person to be getting a VIP invite that night
