Momo, a busty and horny married woman suffering from a sexless marriage, is invited to a wife-swap by her former senior and department chief from her OL days—a promiscuous couple. Excited and nervous, she gives in to their temptation. While sucking the senior's endlessly energetic cock, she calls her husband on the phone. Originally planning to spend time alone with the former chief, her husband suddenly shows up, heightening her arousal as she has sex under his watchful eyes. With her husband's erect cock in her mouth, she becomes drunk on pleasure as another man's shaft violently pistons her pussy, captured in the throes of utter sexual abandon—a truly insatiable wife lost in ecstasy.