After six sexless months with her boyfriend, Yui visits her ex, Taro. Talking never stood a chance: he quickly strips her, and she convinces herself that sucking cock is not really cheating. She thoroughly licks her ex's cock and ultimately swallows his cum. Days later, Taro visits the apartment Yui shares with her boyfriend. While the boyfriend showers, Taro gets horny and the pair secretly begin another blowjob, nearly getting caught and savoring the thrill. Once the boyfriend is predictably put out of commission, they leave him behind and indulge freely. Forbidden desire and guilt collide in this illicit cheating fantasy.