Yuri and Natsu are two close mom friends who are increasingly frustrated with their husbands. A drinking party at Yuri's house begins, but as they get drunk, it turns into a contest to badmouth each other's husbands. They exchange jokes, saying things like, "I'm jealous of your husband." Gradually, they begin to discuss their frustrations with their sex lives at night... Then Yuri's husband shows up. The three of them then go back out for drinks. Natsu, who has had a history of sexless relationships, boldly confesses, "I actually tried swapping partners the other day!" Surprised, but unable to hide her interest, Yuri accepts the suggestion in her drunken state, and Natsu immediately invites her husband over... It's a thrilling night filled with a sense of immorality as they embrace each other's spouses, a mixture of jealousy and pleasure. With their rationality thrown out of the window, the four women's desires are soon engulfed in an unstoppable orgy.