His sister-in-law had a fight with her boyfriend and ran away from home, but his wife was working overtime and didn't come home, so his brother-in-law, who seems to be a serious man, was left to deal with the situation alone. The cause of the fight seems to be a lack of sex, and he is seduced by his sister-in-law in a drunken state, wondering if he is attractive. He knows it's wrong, but he can't help but get excited by her younger and more erotic body than his wife, and he becomes addicted to her pussy.