Bearing in mind her Dads penchant for touching up her ex husband and having relationships with barely legal young men and making sexually inappropriate comments about his own children (showing that he has very questionable morals of what is acceptable - not because he's gay, to be very clear), I'm not sure whether it might not be a huge leap to say he knew exactly what was happening or even was possibly guilty of some abuse of others himself. Doing and saying nothing at all to your childs abuse is not a normal reaction.
In hindsight it seems obvious now why Nick always seemed deeply uncomfortable around him
In hindsight it seems obvious now why Nick always seemed deeply uncomfortable around him