setting doesnt mater. But I like it when the MC is not a tiny dick loser. If you give the player choices, the obvious choice that should realistically avoid NTR should instead lead to it. I want the MC to make all the correct choices but still lose to the clearly worse guy.
I like the guy that steals teh girl to be clearly the worse guy, either an ugly bastard or playboy that the girl outright hates at first, but she eventually falls for. But without having to resort to midcontrol/hypnosis/drugs.
I want the NTR to catch me off guard, not something I have to actively make the stupid choices so it leads to it. One of my favorite games is Lean 2, because its a long build up, and at one point you send the girls to teh capital to be safe while you defend the border in a decently long fight. And when you go back to teh capital, BAM! The Noble that was an asshole made himself king and is fucking the girls, including the kind one that nursed you back to health one time, and teh feisty one that always talked shit about the noble, lol. Game kinda get boring after that, and the non king routes are mea. But that one scene made the game one of my favorites.