My daughter started living together with her boyfriend, so I came by unexpectedly out of concern. However, despite my presence, both of them continue to show no shame in their lustful behavior. One night, while lying down in bed in a river formation, I hear faint moans coming from next door. Despite knowing it's wrong, every time I hear rustling sounds, my body responds with arousal. Finally reaching my limit, I decide to take matters into my own hands when they fall asleep. I climb onto my daughter's boyfriend and initiate some intimate cuddle sex...

彼氏と同棲を始めた娘を心配して、突発的にやってきてしまった千里。しかし千里がいるにもかかわらず、イチャラブを隠そうともしない二人にドキドキさせられることに。夜、川の字で寝ていると隣から聞こえてくるかすかな喘ぎ声に疼き出す身体。いけないとわかっていながらも、衣擦れの音が鳴るたびに千里のボルテージも上がっていく。遂に我慢の限界を迎えた千里は二人が寝た隙に娘の彼氏に自ら跨り、添い寝セックスを決行してしまう…。