As far as the Harem tag goes............................ to me, the sexual notion of a 'harem' implies the same dick claiming multiple female partners, and the knowledge that all participants are aware of each other's "membership" in the Dick Club. So there are a few potential subsets for that: Roxxy-Becca-Missy; Grace & Odette; Diane & Debbie. Thinking about it, those are the only combination of partners that are aware of each other (and participate in gleeful sexual congress together) in the game. Jenny has pretty much sussed out that MC is dicking Mom and Aunt Diane and she still plays hide-the-salami with MC, but that doesn't count for these purposes as Mom and Aunt Diane don't know that MC is playing hide-the-salami with his Sister. It seems clear that Mia figures out MC is boning Helen, but if you chose that path you can't bone Mia, so it doesn't count. I can't remember if Melonia and Iwanka are aware of each other's relationship with MC. As far as I can recall at the moment, those are the only potential 'harems' in the game.
I mean, strictly speaking, 'harem' simply refers to female living quarters. So this notion is sorta skewed to begin with.