Agreed. MC is supposed to be slow but not
that slow to not realize.
Tbf though that scenario is just so absurd, his mind rather accepts what he wants to accept as truth, which is gf being hungover, having headache, might be throwing up any second, etc..
Sudden monke brain MC is an overused ntr trope but it was too hot not to include.
Thanks for the answer)
The dumb MC in NTR games is the most common stereotype.
For me, this only works in kinetic novels (in my opinion, most of the most notable NTR games are kinetic novels), where the main task of the protagonist is to be a cuckold and suffer.
I can smash my face with a facepalm, complaining about the stupidity of MC, but this is roughly a film, and I'm just a spectator.
In games with a choice, my personal preference is for the MC to somehow more or less adequately act on the situation.
Therefore, personally, in my opinion, games where you have a choice, the genre of "mysterious NTR" is more suitable, when you definitely cannot say whether a girl is cheating on you or not, when you constantly question your actions.
"Or maybe I'm wrong? Maybe starting a quarrel with her without proof, I will push her away even more, and I will look even more jealous idiot?"
Right there, already in the first chapters, MC has evidence, besides, another man puts his hand between your girlfriend's legs a meter away from you, and that's why I am so annoyed by the lack of an adequate response.
EDIT: That is, roughly speaking, either a story where you have no evidence, or an adequate reaction to what is happening, even to the detriment of the relationship.