AITA for refusing to invite my sister’s kids to my wedding because they don’t believe in “mixed marriages”?

I (28F) am getting married to my fiancé (29M) in a few months. I’m white, he’s Black. My entire family was supportive—except for my sister’s (35F) family.

Her husband is extremely religious, and they’ve raised their kids (12M & 14F) with the belief that interracial marriage is “unnatural.”

A few weeks ago, my nephew made a comment about how he “doesn’t understand” why I would want to marry my fiancé. My niece agreed, saying they were taught that “God prefers people to stay with their own.”

I was horrified. I asked my sister if she seriously allowed her kids to think like this, and she shrugged it off, saying, “That’s just how we’re raising them.”

So, I told her they’re not invited to the wedding. I’m not going to let two kids raised with racism come and sit there judging my marriage.

She flipped out. She called me intolerant, said I was “punishing children for their parents’ beliefs,” and that I was being just as bad as I accused them of being.

I told her, “No, you’re punishing your children by raising them to be racist.”

Now my entire family is divided. My parents think I should “be the bigger person,” but my fiancé says he won’t feel comfortable with them there either.

AITA?