I've heard the ethnic background/culture arguments, too (although in my case, it was all about how in his culture, it was accepted and expected that people yell and scream and throw things and call people names when they get into an argument.)
Here's my thing: Just because something is accepted in one culture doesn't mean I have to accept it in my life. There are people who believe that honor killings, female genital mutilation, animal sacrifice, and forbidding women to wear pants respectively are important parts of their culture. I still refuse them in my life.
It's not about what's acceptable to him. It's about what's acceptable to you. And only you can determine what is and what isn't.