[originalmike]

Well this all really depends on how he asked you to stop the first time. If he asked you politely then you probably should have stopped, but if he was an asshole about it then you have no obligation to make him happy.

My family is Russian (but we live in the U.S.) and my parents both work at the same company which also has some other Russians. My parents understand that some people take offense when people talk in a different language in front of them, and they try not to do it most situations. But when people who originally speak the same are just socializing its ridiculous to expect them to speak a language that is foreign to them. In the case of my parents and other Russians, they wouldn't even understand each other with those accents.

This guy sounds like he needs to chill out and be more accepting of people at his work. If he is so anti-social and/or racist he probably shouldn't work at a place where there is people.