This is a fanfiction story continuation of NTR ero manga "Boku wa Tsuma ga Netorare Nando mo Ikasareru Sugata o Mitsuzuketa" or "僕は妻が寝取られ何度もイかされる姿を見続けた" by sanku.
After reading spectre699-san's story, I was inspired again by him, here is my take on the series.
The story in the manga is basically, the wife is not getting enough sex from her husband so she's secretly cheating on her husband with her ex-boyfriend, but the husband discovered it, but pretends to not know it.