Yeah, I kinda feel that myself a little bit as I'm wondering why the MC, who seems like a prefectly nice guy, would go down a path of trying to dominate them and make them submissive. Just doesn't seem to fit his persona.
I think the perving stuff is fine though because he is, after all, a grown man who's just taken in 3 gorgeous young girls that resemble someone he knew and liked when he was their age and has had sex dreams about for many years, so why wouldn't he be turned on by them? It's just the domineering path that I don't think fits his character.