Thank you all guys for all the replies. It's nice seeing other people's opinion regarding a very controversial fetish. Usually it's hard to discuss this kind of topic in a civilized way without getting called out in all sorts of names. Good to see this thread got a lot of respectful people
Other than that, I came across something very very interesting while I was playing a non-H 3DS game named "Persona Q". There's that event called "Group Date Cafe" in which you pair one character with the MC, who then will go through a fake marriage trial as a couple. Y'know, for the longest time, I was wondering how it would feel like to watch/play a crossover title that combines two harem series, and Persona Q just gave me the perfect answer to that, as that game combines two widely popular titles named "Persona 3" and "Persona 4". If you're a turn-based JRPG gamers, there's high chance you know about them. Before you can begin playing the game, you need to choose which MC you'd like to control, whether the one from P3 or the one from P4. Now you can guess how it flared up my interest, since the event basically gave me the chance to see how the female cast of one harem series would react to the advance of a MC of another harem series. What I basically did was have the MC of P3 pair with the female cast of P4 and vice versa. And dang, was it a hilarious and refreshing experience. It's not NTR technically, though the feel was still there, a positive kind of feel, especially with the two female characters, Yukari from P3 and Rise from P4, who are canonically in love with the MCs of their respective games. Besides, I got to see another side of them, especially Rise whose dialogue with Minato (the MC of P3) actually had more personality compared to her usual fangirlism over Yu (the MC of P4, who she was originally meant to be with). Here's a full vid of the event involving the two girls I'm talking about:
https://www.youtube.com/watch?v=-KF0P5I2Jns&t=627s&ab_channel=justonegamr
https://www.youtube.com/watch?v=LtJPXl-NEZ0&ab_channel=justonegamr
(Really like those YT comments haha. The persona series is one of the very few japanese games where I prefer the EN dub over the JP dub. The EN dub is just that good)
I seriously love it when I find those tidbits of NTR moments in a title that is meant to be full Vanilla. Hopefully I can find more like this. There's Fire Emblem Fate too with its romantic pairing system, but it's not as explicit