Yui are friends who live together. Yui has had a habit of cuckolding since her school days, and even now that she's grown up, she still seduces Ria's boyfriend. After getting him erect with a blowjob and a titty fuck, she has sex with him in a crab-legged cowgirl position, shaking her hips! Ria witnesses the scene and gets into a huge fight with Yui... but Ria chooses the friendship of women over men, and suggests that they have sex together, saying, "If we share our boyfriend, there won't be any fighting." They line up their pussies, finger each other, and give each other double blowjobs on the boyfriend's dick, and then they moan and shake their hips together in a threesome that deepens their friendship!