[Benitenchi (Dentaris)] Kyokon Otokonoko ni Kanojo ga Netorarete Jibun mo Okasareta Hanashi. [mysterymeat3]

A hung femboy sets his sights on an attached couple, and the girlfriend crumbles fast — one taste of something her boyfriend can't match leaves her drooling and daydreaming about where else that size could go. When the boyfriend stumbles onto the affair, there's no confrontation; he wakes up instead dressed in his girlfriend's lingerie and wig, his modest endowment teased while the smirking interloper promises to make both of them feel good from now on. A cheeky netorare where cheating is only the opening act and the real prize is conquering the couple entire.