You obviously are being unreasonable OP as you already know, you are both damaging your kids by constantly arguing in front of them. Get it together, seek therapy, divorce but don't argue in front of the kids, it's not their job to have to deal with your communication issues.
Your DS will probably feel guilty if you do divorce because you have been arguing about him constantly IN FRONT OF him, he shouldn't have to feel like he is responsible for your fallout (even if he is).
That being said what are YOU doing about your DS's challenging behaviour? your husband constantly calling him weird is obviously not healthy but it does seem like your son barely listens to anyone and he sees you continuously defending him, it seems like your DH is at the end of his tether. I agree that supporting toxic reactions isn't on but you DO need to be a team in front of the children. Does your DS have any consequences for his misbehaviour? You both really need to agree on an effective punishment for your ds. Your DS shouldn't be allowed to continuously misbehave and disrupt dinner time or other family time to the point where everyone is shouting and yelling at each other.
Your DH calling him weird is wrong but your DS's behaviour is also wrong and need dealing with. Instead of calling your DH a prick who should fuck off for losing his cool (losing yours in the process) saying "DH, I don't think you calling him weird is beneficial nor called for here but DS your behaviour is definitely out of order and you need to cut it off as we do not tolerate this type of behaviour around the table. If you can't control yourself, early bed time and no TV tomorrow (or whatever other punishment you would want to implement) might be the solution."
It seems to me like your DS walks all over you, your DH obviously doesn't know how to deal with his constant misbehaviour and has turned to shouting and yelling and you seem totally unable to deal with either your DH outburst or DS's behaviour. Family counseling seems to be greatly needed here as you all seem to have chosen yelling, swearing and throwing tantrums as your way to communicate with each other.