Interesting! I liked the way this was going already, but the centaur has really added a brilliant twist to the whole thing.
Laurel's a nice name for her, I think. And her innocent cluelessness about things like human nudity taboos looks like it's going to make for lots of fun. "My Stallion" as a title is perfect; I wonder when/if she's going to realise what it sounds like to humans?
Oh, in case I've spent too much time on Laurel, I have to say that I love your characterisations of Luna and Susan as well.