I dont' know you or your husband. Ther eis certainly the gut reaction to assume he is just a jerk. But he may not be. My husband has torucble talking about things and internalizes it rather than deals with it. Maybe your husband has the same problem but he erupts instead. Either way, it reflects a certain immaturity. I believe you rpobably want your son to inherent the best parts of your husband. But namecalling certainly isn't one of them. My husband and I have never once called our children a nasty name. And I want them to grow up to be kids who treat others better than that. So your husband may have some great qualities, but communicating with his son simply isn't. I would bet money tha the wasecposed to this language as a child too.
I don't believe we should treat our friends and co-worker better than our families, be it children or spouse. I certainly hope he doesn't treat you as he treats his son. Maybe he does and then youu have bigger problems. If he is in a bad mood, tough. You have a right to say how your child is talked to and you are his only line of defense. WOuld you let a teacher or coach toalk to him that way? WOuld your husband let himself be talked to that way? Doubt it!!
Don't let your son be assaulted with words which are mean - and really just counterproductive. What does your husband think is helpful about namecalling?? It makes him feel better but is in no way parenting or disciplining. It is simply him taking out his frustration and shows he can't put his thouhts and words together well enough to actually try to resolve a problem. YOu and he need to discuss discipline and a plan. "Next time Billy does this... then we will.." Maybe you need to send your son out when he misbehaves, discuss a punishment wiht your husband, and then you dish it out. If you can't say something nice, don't say anything at all.
Hie is teaching his son how to talk to others. What kind of man do you want your son to be? One who namecalls or one who is a problem solver. Tell your husband about all the great things he does show his son, but you need to draw a line with behavior that is unacceptable. Be strong for your son!
PS - Just reread your post. If he talks to you the same, he must stop. I think everyone acts out occasionally and says something nasty to someone they love. However, ongoing namecalling an dnastiness is not okay. You can fight, argue, even yell, but it sounds like his weapon of choice is degrading everyone else. It is immature and useless. I suggest you lay down the law. Next time he acts childish, walk away or drive away. Don't let him talk to you at all until he can talk with respect. Your son sees that you accept it an dhe will come to acept it too - from his dad and others. And his wife and kids will have to deal with the same thing from you. Also, I wouldn't be surprised if your son starts treating you this way when he is a teenager. Totally not okay. Please don't fool yourself. Most husbands and wives dont' talk to each other this way.