It's part inherent, and part, well-- when you get down to it, logically, the human Ai is the real Ai by all standards. While she definitely got used to be a succubus, most of her life, she was still a human. Which is why he'd still feel terrible either way.

Funnily, Seku actually really prefers lithe figures more, but buxom isn't bad. It's cozy.

How does the Owner see Seku, since he's a pretty regular customer of his and has some personal liking on his part.