A little bit of biting can be cute, especially if she licks the wound afterwards, so adorable. I like how he just bites her back though.
I must say, his calm and cool analysis of everything and explaining what's going on pretty much all intellectually-like, was really interesting. Even that ending where he explained his plan to bait a reaction for sex.
Nothing wrong with transitioning into becoming lovers after that though, if you ask me. Who knows, maybe a few more bites will change his mind.