So my whole life I have been taught to Respect my parents. I would never swear around them, or say "dirty" jokes (That's what she said, Your mom, etc.) Now my step dad's son constantly tells him to Fuck off and other such profanity. He lives with us, rent free, and yet he says this to his father. His father even swears back!
Because of the way I was raised I feel like this is vary wrong. I want to know what all of you think about this. If your a parent, how would you respond to it?
EDIT: He is 21