Obviously, the pledgemistress will claim the man was one of the ones she didn't suck.
I'm pretty sure the big sisters will decide they like it.
Part of the test is working out which dirty old man has the antidote.
It's the best-funded sorority in the country.
The reasons are that she makes men hard and women jealous. Well, you didn't think she was referring to her boobs, did you?
If she hadn't done as requested, that would have been used as an excuse to kick her out of the sorority. It's what happens when the big sisters realize their boyfriends are lusting after the pretty pledge.