Infrequently a game comes along that you can become immersed in to greater levels. No matter how amazing the renders, plotline or character development is, I have never felt personally distressed or become unhinged due to the introduction of or an event including NTR.
You would have to suspend all logic and rationale to become emotionally distressed because a CHARACTER created by a developer, outside the realm of your control or knowledge of your existence, is third party to or observes a sexual act without being the primary and relegated to bearing witness.
Forget the element of being so self absorbed you think you are the literal character inside the game that's completely unrelated to you, let's explore how emotionally stunted a personality has to be in order to take a personal offense to something wholly unrelated to them. It boggles the mind.
You are not the MC.
You weren't a thought in the devs mind when he created the game.
The content, no matter the genre, is not intended to upset your delicate psyche.
If you don't check the tags before starting a game and discovering the presence of NTR content that's on YOU.