29-year-old aunt claims her 32-year-old brother is not his 9-year-old son's real dad because he adopted him when he was 3, brother blows up at her: 'She said I am too sensitive because he is not my real kid.'

He is his father, no matter what she says.

I don't care what your family situation is: it's not okay to tell kids that the parental figure in their life is "not their real mom" or "not their real dad." It's not okay to say when a kid is adopted by someone who is not related to them, and it's not okay when they're adopted by family members, like an aunt or an uncle, either. Family members can have roles that differ from what society expects. Babies can be uncles if grandparents are having babies after their kids. Older siblings can become parents to their younger siblings if their mom or dad is not fit to be a parent. Familial roles can be incredibly fluid, and just because society prescribes the nuclear family model of one mom and one dad as the end-all, be-all doesn't mean you shouldn't step up when you're needed and fill the familial roles that are appropriate for your family's unique situation. Any person who chooses to raise a child that they did not parent biologically because the child's biological parents are unable to do so is a saint as far as I'm concerned.