Hi! Sorry for the late reply!
There are positive polycule endings in the game, but there is one particular route you can go where the player can cheat on a character if they don't clear up a misunderstanding. However that choice will be very obvious and is avoidable. It is also not written to be a positive choice for the player!
Cheating is never positive nor kinky, even in fiction! I agree with you there. I also don't think it's a bad thing if the player decides to sleep around and have fun without any strings attached! I don't want to spoil too much but it will be an obvious choice with a warning if you do go to cheat.