DS should be learning independence, yes, and other things as well. As a man he'll probably be more physically powerful than most woman and, I feel, should always, when speaking to them, be polite or demonstrate a certain control over their tongue and body. I agree arguing back is counterproductive and I'd suggest trying two things. Males, I think, get more out of visual cues and actions than verbal communication. I think a look that expresses fury at what's being said with a little hurt that it could be said directed nonverbally followed by a cessation of all communication might temper him; a flash of eye contact and it's over. I also think his father should have a talk to him. "Break windows and curfews but DO NOT presume to speak that way to my woman and your mother. I thought of a third thing. One or more of the Calvin and Hoobes cartoons has Mom and Calvin speaking as if they're in King Arthur's court. I think I recall Mom saying to young Calvin something like, "Is there any devilry thou hast not yet commited?" Maybe introducing some play into your dialog with him might diffuse some hostilty especially if he assumes some of the necessary politeness of a young knight as he speaks to you.