Is AUTHOR wrong in the post ? POST : My girlfriend calls people "boy/girl" sometimes the way I would say "dude" or whatever. Several times when hanging out with a black male friend of ours, she's called him boy in the "damn boiii" kind of way. He's never said anything about it, or even visibly reacted to it, but I can't help cringing every time it happens. 

I assumed it was common knowledge in the United States that white people calling black men "boy" used to be a common, demeaning, and racist phenomenon, but when I told my girlfriend "hey, maybe you shouldn't call ___ boy anymore," she had no idea what I was talking about. She insists that it's not a big deal, I'm overreacting, and that's just the way she talks, but I'd rather not take any chances making our friend uncomfortable, even if he knows it's not intentional. So, AITA?