The relationships aren't mutually exclusive at the moment so it feels like harem is still in the cards (maybe not in a way where you end up with all the girls in a big mansion but rather in a way where you don't miss much content in your playthrough if you want to be a womanizer?).
Ruby and Emma are good buddies, I'm sure they'll be happy to share down the line even if they're a bit possessive when it comes to who's got dibs to jerk you off during your sleep
And a threesome is already coming our way with the two naughty sisters! ^^