Hey Mecha, thanks for the feedback.
There is no female only option, but I will consider it. You can turn it off if you like having the characters run around the hotel naked and prefer that they aren't seen. If you train exhibitionism then the game will assume you're okay with public nudity. It's all optional, these fetishes are elective.
Many of these guests will be friends and foes you've seen before. There are "bad" guests that I expect most people will refuse, and that's a part of the fun I think. But... I think it's a bit of a stretch to say that men being in the same public space as your girlfriend is cheating. They don't even acknowledge each other's existence.
Guests are not residents though, they're not being added into the story or the harem. This is only a gameplay mechanic.