I read this BL korean manhwa, but forget the title. The story goes like this: a couple from a noble family have been trying to have an heir, but after years still failed. So they ended up adopting a baby boy (or it was an illegitimate child between the husband and a mistress, I forget) as the official child of the family. But unexpectedly the legitimate wife gave birth to 3 sons not long after that. The youngest son (our MC) is just a guy, who enjoys life. He tried to bully the adoptive son, but they ended up fooling around and sleeping together.
I read this BL korean manhwa, but forget the title. The story goes like this: a couple from a noble family have been trying to have an heir, but after years still failed. So they ended up adopting a baby boy (or it was an illegitimate child between the husband and a mistress, I forget) as the official child of the family. But unexpectedly the legitimate wife gave birth to 3 sons not long after that. The youngest son (our MC) is just a guy, who enjoys life. He tried to bully the adoptive son, but they ended up fooling around and sleeping together.