And it was a good thing too, given he was the last creepy Cardassian on the station.

I always got the impression that his only motivations for hanging out with her were having another Cardassian to talk to and pissing off Dukat.

Andrew Robinson has on many occasions said that he played him as “omnisexual,” and that he definitely had a thing for Bashir. As for his interest in Ziyal: it’s obvious that he was lonely being the only Cardassian on the station and appreciated her company.