@Blueberry_McFuckerson: You're forgetting one key factor: Like any good spineless, male MC, he doesn't care, or is too agreeable to care, that this guy is targeting his own little sister. He even took Mahiru to sit and talk with this guy, when anyone with two neurons to fire impulses between can tell he's only out for sex, and the "love at first sight" business he was spouting was just his finding a girl who doesn't bore him like the dozens of other girls he's gotten tired of.
If all of the thawed men in this series embody some sort of vice, this is Reito's. This is not innovative, however, because he's inherited this spinelessness from so very many male harem MCs that have come before him.