Fuufu Koukan Modorenai Yoru Married Couple S Exclusive < INSTANT – 2025 >

Often found on sites that host "AnimeFesta" (formerly ComicFesta) titles.

It seems you're referring to the adult visual novel / eroge title: (夫婦交換〜戻れない夜〜) — often subtitled in English as "Married Couple Swap: The Night of No Return" . fuufu koukan modorenai yoru married couple s exclusive