It takes a mature and well articulated person to understand that some people can't control their emotions when they're furious, so the best thing is to understand the kind of person you're dating or your partner .If s/he is the temperamental type even if s/he abused you in public s/he would still comeback and apologize to you.
Insulting you before his family only shows that he/she has simply been dropping one or two negative jibes about you to the family before hand. How you react will either confirm or negate it. Simply ignore the insult. Silence is more powerful than you think. It can even be really loud sometimes. Don't forget to discuss the issue with him/her as calmly as possible when they leave.