Yeah, I mean, I personally didn't consider that scene to be NTR either. To me, it was just another one of the game's patented fucked up sex scenes, which don't bother me, but I also don't think add anything to the game.
With that said, I can totally see how other people would consider it NTR. I don't think people bothered by the scene are "overly-sensitive-to-anything-anywhere-near-NTR people." Some people view girl-on-girl the same as guy-on-girl and I do not think that's inherently wrong. If anything, it's probably less sexist. And I can see how getting NTRed after years of investing into a game and characters could make people very upset. And that scene clearly turned some people off the game.
I think it's a very weird choice for Selebus to be adding more things that border on NTR to this game, because if he keeps edging the line, he will just push more and more people away. Maybe he's trying to hurt a specific group of people who play the game. But...
why???? His game has not grown in years. His Subscribstar's back down to 9.8k. He
lost subscribers after this update. And he's been adding custom non-cannon renders to the game and setting goals to try to get more money recently, so it clearly matters to him. It just feels like he's shooting himself in the foot. I want to see this game finished eventually, and at the rate he's going I'm worried at the very least we might eventually get much longer update times if he needs to get a real job to support himself.