Not really a NTR as "MC" is kind of an asshole and a dimwit, and the story is often not told through his perspective anyways. The other man (James) is not "stealing" his woman, as she chose him willingly. In some sense this feels like a netori or a simple cheating story, as you don't really feel any jealousy from the cuck's POV, he doesn't even care about his wife as much as he does about his own pride and ego. Besides James is a really nice guy, he didn't even know that the FMC was cheating on her husband with him, and even after finding out, he STILL proposed to her. Yeah, bro this is not netorare in the slightest. Kinetic novel BTW, as there is only a single choice which doesn't affect anything at all. Very short, nothing stands out apart from nice visuals, hence average rating.