I dont even know if it was added but a threesome mechanic would be lit!
only two moves really have it being spitroast and double pen. doggy. It have happen when the PC is holding hands with another character and they select a different one. Really only have the option if they have a high enough love stat to unlock the moves. (You can also have three of the NPCs have threesomes by using the command hand on two different characters, while the PC is holding hand with a third one)