The Strongest Live-In Son-in-Law in Another World

Li Mu brings a System that lets him level up by killing monsters when he transmigrates to a world where martial artists reign supreme. It sounds like a dream come true, but... what kind of move is selling his wife from the start? His mother-in-law: “My daughter is breathtakingly beautiful, and you're just a useless, lazy bum. Get lost!” His father-in-law: “My wife is right!” One month later. His mother-in-law: “Son-in-law, I was wrong. Please don't leave, I beg you!” His father-in-law: “My wife is right!”