- Real Father
That depends on the specific situation.
Is one of them closer/more present in the boy’s life than the other, or just has more of the boy’s respect? In that case, it should be the one who’s closer to him.
Are they equally present in his life? Then they might both scold him separately, unless one is stricter than the other, in which case have the strict one scold him.
Is the stepfather the real father’s husband and not his replacement? Have both dads scold him at the same time, since this seems like something both parents would do together anyway.
NO! His stepfather married his mother!