After he cut me off for the tenth time because "duh mom, I already know that!"

Me: Warren, you have got to quit talking back to me and interrupting me.

W:  Sorry.

Me:  It's rude and disrespectful.  And I know you aren't either of those things, so it needs to stop.

W:  It's just a habit of mine.

Me:

Me:

Me: Well, it's a bad habit and you need to break it.

W:  I know, I'm trying.

W:

W:  It's just not going so well.