My current favorite tag: #nothing can really fix londo

Which remains no reason for him not to have the chance to get railed!

and for Londo at least it's a little less out of character because he does have this tendency towards being very intense in some of his relationships, and getting attached very suddenly and profoundly (see: Adira)

Agreed! But it works from the other end of the spectrum, too: through his relationship with Refa, we get a fairly good idea of the norms of Centauri rivalry. Even at their most openly antagonistic, Londo is still not normal about G'Kar.

(Talking about science fiction by way of other science fiction, I associate them strongly with Le Guin's concept of ontá, the emotion which is love when polarized in one direction and hatred when polarized in the other, but is otherwise all the same state.)

but for G'Kar, it really is wildly outside the way he normally relates to people, even those he loves a lot.

Yes. You really can't imagine him letting Londo go. He'd check up whenever he got back from the galactic tour.