If Drexel could fuck a kid he knew when she was 13, even though she's legal, then you can guarantee that he never saw her as a child at the younger age to begin with. He would have flirted with the girl, and the mother would have found it "adorable".
It's repulsive, and anyone who's been around kids that have then grown up would know that, most men I know would baulk at the idea, because they can see the child in the adult.
Plus, you don't fuck your friends kids, regardless of age, you just don't.
It's dodgy as hell, and it confirms his morals, which are those of an alley cat.