Meh.
If she were 14, I'd see the outrage.
She said she was a couple days shy of her 18th birthday. If this took place a couple months from now, but she was exactly the same age, she'd probably be a college coed. Age of consent is actually 16 or younger in most states.
Not that this is exactly the case, but I've got a hard time thinking someone's a monster for fucking a chick at 11:59 the night before her 18th birthday, but he's a hero for doing it a minute later.