The man is insecure about why his wife married him but never bothers to ask. He thinks she is wasted on him and it is tiring to read about his suspicions about his wife when she has yet to do anything wrong.

Let me give you a better and clear summary of the story. It's about a loser, whim middle-aged guy who for absolutely no reason received a lottery in the form of a wife, who not only is beautiful and young but is very devoted to him. Despite all these, this mf is suspicious of her and if that's not enough he suspects of her for every kind of wrong doing and not a single moment in the manga you see where he sees her as herself. Dude could get a divorce or just straightaway asks her if he really is so desperate in need to know about what goes on her mind. He is your typical loser manga guy who doesn't know how to appreciate good things. It's not comedy when you make insecurity and suspicion of someone for no absolute reason.