children yelling at parents

I'm so disgusted by children (or grown adults) who yell and cuss at their parents! My husband said his childhood was bad so he has the right to be mean to his mother. Today we took our 6 month son over to their house and lilo and stitch was on. My husband said "oh mom we never watched Disney movies because our childhood was so terrible" him and his brother (both over the age of 20/23) start cussing at their mother who's making us dinner saying their childhood was shit and she ruined their lives.. his brother then told his mother to shut her mouth. I am DISGUSTED. We are in her home and she's cooking us dinner. She does everything for my son. He claims his childhood was bad (had to move around, had an abusive step dad) but I'm sorry get over it. A lot of people had bad childhoods. She is amazing to us.