It's really impressive how oblivious the mc can be. He really should recognize his own wifes body by now. He should also know what sweat and semen looks like. He should also know what ruined makeup looks like as well as what pubes look like. There's also the very weird sounds that happen when it's only the mc, his "friend" and his whore of a wife in the house and his wife is nowhere to be found. He should be able to put things together and figure out his wife is cheating on him right in front of him.