Do-hoon, who started living with his mother-in-law Mi-ae at the request of his wife So-jeong, feels a strange attraction to his wife’s stepmother, who is younger than he expected. Then one day, while Do-hoon is trying to have a hot time with So-jeong, the couple gets caught by Mi-ae. Mi-ae then asks her stepdaughter and her son-in-law for a secret favor.