Guh. I agree, it's good that she's upfront about stuff, but that guy was just out to humiliate her. There are certain kinds of people that really grind my gears, and out of all of them, #2 is people like this guy.
If he says he has loved her all this time but has nothing to prove for it (I care nothing about being a virgin or not, but don't claim something you can't back up), then gets offended when she gets upset when she realised that he had played her for a fool, THEN he manipulates her into treat her like a servant in front of their classmates. Sorry, this guy deserves jack shit.
Ugh, honestly that girl's no good either... the guy infuriates me but the girl annoys me as well. I think this whole thing just makes me angry >_>;;
Ryuunosuke-kun wa Yasashikunai