Ore no Yancha na Otouto ga Shiranai Oji-san ni Kawareteiru

"Oh, did you find out I'm a sugar daddy?
See, I'm a hottie, you know?
I'm cuter than the girls around here, so I can make more money.
Well, it doesn't really matter to you, bro, right?"

My little brother is being kept by a strange old man.
He receives money from his "daddy" and has relationships with multiple older men.
He's a troublemaker, a bitch, and loves sex.

"Hey, bro. You were secretly watching me having sex with that old man, weren't you...?
Was i cute back then?
Do you want to do it with me, bro?"

Will I tell him to live an honest life?
Or will I join him in his downfall...

[From Dlsite]