I hope you took his breakfast away when he said that op!
His dad should be stepping in hard and stamping down on this behaviour, “do not speak to your mother this way” or “no one is disrespectful to my wife including you”.
And similarly, you must keep very calm, straighten up and look him in the eye op and say things like “speaking to me like that is unacceptable” and make sure you never respond to him when he is rude other than to tell him it’s wrong. Do not engage in back and forths. Leave the room. He does not get your attention full stop until he can speak decently to you.
And of course follow through with no lifts, turning off wi-fi, losing part of his allowance, more chores, or whatever you decide is fair.
Obviously, if he has ASD or ADHD, that will affect his impulsivity and his ability to assess how much he is hurting you, which all teens are bad at understanding anyway.
My daughter with ASD would sometimes “chase dopamine” by causing an argument or bait me when she was bored or couldn’t identify her own feelings, but knew she was angry or upset, but couldn’t express it properly. So allowances have to be made, but ultimately every child or teen needs to learn what is acceptable behaviour and what is not, for their own sake as much as ours. The outside world is not going to be as understanding as we are.
Another approach is, “if something is troubling you then you can talk to me about it reasonably and I’ll listen?”
Try and listen to the emotion behind the words and not to the words themselves.
Are they bored, frustrated with having too little control or responsibility, plain mischievous, trying to engage in power games, or genuinely upset about something? That will help you to choose your approach but the base line is that rudeness and disrespectful behaviour is unacceptable.
You can pause and take a long look at him and say, “you disappoint me when you speak that way” or “I thought you were cleverer than that”.
Sometimes you can use humour to deflect “yeah yeah my nose is at least six times as big as yours, now get your yourself downstairs for breakfast please”.
We have dds but once when my dd with ASD was really rude to me, my dh stepped in and said “your mother and I are going out” and I was half way through cooking dinner. Her sister was out, so my dd got left alone, with no dinner, and dh and I stayed out late, and that got the message through that being rude led to immediate disengagement.
Alongside that we pushed the message that if is she was unhappy about something, she had to speak to us respectfully and we would listen. Of course they need help regulating themselves, so they may not always get it right, but encourage even the smallest attempt to self regulate.
And you and his dad must be very quick to pick up on any tiny positive thing he does - can be hard at this age 😀 - and praise him a lot for it.
Look after yourself too op while this is going on, because it’s so draining and upsetting. Treat yourself to nights out. Exercise. Build up your self esteem so your are not susceptible to any ridiculous insults. Don’t take what he says to heart,
Take up hobbies you enjoy and makes you laugh. Confide in one trustworthy friend who won’t blab and has teens themselves. Go out alone more often and out more often with your dh. Bring your friends home. I’m sure you are not, but don’t give your ds any reason to believe that you are the little woman at home there to serve everyone else’s needs. Maybe hold off delivering breakfast in bed for a while while this behaviour is going on! 😀. Good luck.