Looking for a manhwa

The story starts with this guy doing it with another, much older, for money. But it comes out that this older guy is his mom’s new lover and lowkey his new stepdad. But the new Stepdad wants to keep fucking the son. And to come out of this relationship he tries to get this guy from school who is obsessed with him to frame the stepdad. But I think that fails and in the end his mom has a sort of break down?

I remember this one part where the stepdad made the guy insert something in his ass while in the lift. Pls help me find it Thank youヾ(❀╹◡╹)ﾉ~