Failure of an Uncle

After being caught anal masturbating by his nephew, an uncle gets creampied repeatedly.

Yuuichi is an office worker, 29 years old. He's attracted to his brother-in-law, who's married to his stepsister.
One day, he's caught masturbating by his nephew, creating a lewd atmosphere.
After seeing the huge dick of his nephew, who resembles his brother-in-law, the protagonist, who has an interest in sex, allows himself to be penetrated.
In this situation that he ought to be persuaded against, all his worries disappear in the face of his first time having raw sex.
The uncle gives in to his desires, and lets himself be ruined by a man...

Official Translations:
English (DLsite, Coolmic, MangaPlaza, Renta!), S.Chinese, T.Chinese, Korean