I take your point, but in that case, why torture yourself? Just don't click on the 'Extra' tab.
Or if you only find some of the scenes objectionable, the scene preview image should usually be enough to flag a warning.
Personally, I'm able to compartmentalise enough to enjoy the extra scenes as taking place in non-cannon alternative realities. Without playing that mind-trick on myself, I don't think I could watch any of the extras.
You are right about me, I should just skip the extra scenes altogether considering the previous letdowns.
But admitting that I shouldn't torture myself by seeing the extra scenes, I felt like I needed to voice my opinion because it shouldn't be that way and everyone should be able to enjoy the extra content if the dev approached them in a more sensible way.
For me, it's a matter of common sense: if Nikki's teasing is the most important part of her character in her relationship with the MC, and we are all looking forward to the moment when she and the MC will have sex after such a long build-up, why the hell would anyone think it would be a good idea to have them fuck in the extra scene when they haven't even made each other cum in the game yet?
The extra scenes are a great chance to increase the spiciness of the scenes featured in the real game. As I said, maybe the MC could have continued massaging her boobs until Nikki came, or she could have stroked her cock while she touched her balls. Both the MC massaging her boobs and her stroking his balls are things that did happen in the game so it wouldn't change too much.
Another idea: Nikki didn't want the MC to cum, right? She wanted him to save his cum for whatever she has planned for the following morning in her studio. Well, in the extra scene when she stays for the night she could have let the MC cum. In the actual scene, she kissed his balls; maybe take that a bit further and have her jerk him off while licking his balls and then he can come on her tits. That's way more sexual than what happened in the game but doesn't skip right to sex.
It takes more planning and careful consideration of you want to show, but that's what makes a game stand out.