This is what we call invalidating your feelings. He is shrugging this off when it is very important to you. I would get the Mars and Venus series and learning about "I" statements. This means that instead of saying "you are mean to me in front of other people" say "I am really hurt by your behavior in front of me in front of others". You can work together on this issue alone or with a relationship counselor. This is bigger than how he treats you but also involves he makes you feel. If you want to have a few brief sessions with online counselors you can do that by googling etherapy. I would arm myself with valid ways to communicate your thoughts better than you have to see if that works first. It is in the way you state your case that counts.
Use these I statements to let him know how important it is. You can also challenge him in a polite and straight forward way when it happens. Then he knows he is behaving poorly. He might back down when he is on the hot seat. Some times it is more about timing than the actual way you say it.
Please press accept ; this is the only way I am compensated