y r some people so rude!?

this 1 guy my BFF was dating joined them on vrchat and started calling them a fat bish for no reason, he's always yelling at 1 of us in the group, like the time i said a fact 'bout my BFF and he yelled at me because I said it in a "rude" tone I didn't know he didn't know that 'bout them. but whenever he yells I go mute. thank god they broke up w him!!