My brother treats his daughter like garbage so I love her; AITA for being nice to her? UPDATE

My brother is mad at me because I treat his daughter well while he doesn't care about her.

Embarrassed-Act3763 writes:

My brother has two kids: Henry, who is 17, and Aria, who is 16. Henry is his wife's child, and Aria is his affair partner's child.

While he is a good dad to Henry, he is a terrible dad to Aria. He is the every other weekend dad who does the bare minimum. Unfortunately, Aria has a terrible mom too, so she spends most of her time at my home.

I love experiencing new things like new food, new activities, and going to new cities, and Aria has started to enjoy these too. So, a few times a week, we like to try something new. She also has an Instagram page where she posts everything she does.

A few days ago, my brother called me and said that Henry is upset that I never include him and asked if I could take Henry with me sometimes. That's when I lost it. I asked him if he seriously expects me to parent his son too while I basically had to adopt his daughter.

I told him that frankly, I don't care that Henry is feeling left out, and I'm not going to include him in activities I do with my daughter. He called me an a%#hole both for excluding Henry and referring to Aria as my daughter.

OP provided an update:

Why is everyone acting like I'm completely ignoring Henry? I spend time with him, I go to some of his important basketball games, I call him whenever I have time, and I buy him nice gifts for birthdays and Christmas.

Last month was his birthday, and I bought him an expensive pair of headphones. Do y'all do more than this for your nephews?

Here are some of the top comments from the post:

Agitated_Associate91 says:

YTA (You're the A%#hole) so you are going to take out the feelings you have for your brother out on Henry.

IBelieveInGood says:

I'm so weirded out by all the people saying OP sucks. He sees one of those kids as his own and is the only adult in their life to be there for her, while the other child has two loving parents.

Then, one of those parents, who's also one of the people responsible for hurting the child OP loves as his own, says, "But what about MY kid? He is sad; you should spoil him," without even acknowledging the WHY of OP having to step up like this. He didn't explode on the nephew; he exploded on the sh%tty dad, and I don't blame him. NTA (Not the A%#hole), OP.

basicstove1336 says:

ESH (Everyone Sucks Here). Aria is lucky to have someone who is there for her. But, you are exactly your brother. You feel so much for Aria that you treat Henry the same way your brother treats Aria. Have you ever heard that two wrongs don't make a right?

You COULD be the person that ensures these two siblings grow up with a good relationship. Eventually, they will be strangers now, thanks to both you and your brother being gigantic a#$holes.

What do you think? Is OP right to treat their niece better than their nephew or should they be treating both children equally?