I thought the point was that they were born that way. They were supposed to pick flaws/attributes that were genetic and they couldn't change but needed to embrace. He wasn't born a manwhore, was he?

Granted, Mercedes probably wasn't born with much hair at all, and I'm fairly certain that Lauren wasn't born with her attitude, but the assignment was to pick something that they couldn't change, that they were born with, and his sex life is both changeable and something you wasn't born with.