A father-in-law falls in love with his son's wife, Nanako, who he should never be interested in. Nanako has a lovely smile and an attractive slender body. Even though he knows it's wrong, he can't help but fantasize about his son's wife's lewd behavior. His wife masturbates in a showy manner, and she gives him a gentle blowjob in the bath, and the father-in-law's fantasies grow and grow...