AITA for making my husband call his sister to say the child she bought for $30k is not invited to her daughter's wedding?

Backstory: My husband's sister married a man much older than her when she was in her early 20's. With this man, he was able to provide her the life she wanted. They are both in the 60's now. About 7 years ago, they adopted a child from India. The reason for this was because their son and daughter needed to inherit the family business, but per Hindu beliefs, you need a son or daughter to pass objects of sentimental value (like the family idol) to before you pass. They couldn't trust my husband with this task. They ended up adopting a boy from India to do this task.<br><br>Fast forward to now, my husband's niece (daughter of his sister) is getting married and the family got word of this. The boy was not invited, but his siblings (my husband's niece and nephew) were. <br><br>My husband's niece and nephew are not in their 20's. They have known this little boy since he was 5 years old, he's now 12. They grew up with him and called him family (as their parents forced them to). Now that they're older, they see him as a burden, but not their problem. <br><br>This is where I got involved. My husband's sister is begging my husband and I to take the child for the weekend so their kids can have the weekend for themselves (with their parents) in the city. I told my husband to tell them to fuck off, but he says they convinced him and he was going to do it. <br><br>I told him, no. This child is not our burden. I told him to take the child with him to the wedding and I'll happily go with them. He refused and said it's not worth the family drama and the sister's will hate him. So I said fine, but I am fucking off and will not take the child for the weekend. My husband looked at me and said "don't tell me you want a 12 year old at a wedding" and I said of course and gave him a list of reasons as to why it's ok for a 12 year old to be at a wedding. He got pissed and went to stay at a friend's house. The sister called me and cussed me out so I hung up.<br><br>Am I the asshole in this situation?