I haven't told my mom because I know exactly how she'd react. However, while I was questioning, I did ask her what she would feel if I never had a husband or any children. She told me she didn't know and asked me why, so I told her it wasn't in any of my plans and that I wanted to spend the rest of my life working and traveling. After that, she told me the usual, that I'd "eventually find someone/I haven't really meant guys" (holy hot damn I was most bothered about how amatonormative and heteronormative that statement was). Overall, she was fairly understanding, but I know that's only because she won't take me seriously. Eventually, I will. Probably when I get into college... It really honestly shouldn't be any of her business, but our family upholds a lot of traditions and literally came from nothing (financially) so it's kind of an obligation to stick with each other (otherwise you'll be ostracized and hated behind your back).
As for my dad, he hasn't contacted me since I was a kid for whatever reason, so I don't owe him anything. However, it's because of his absence that I owe my mom at least a "Hey, you know I love you and I'll take care of you when you're old like I promised, but don't expect any grandchildren. You can expect dogs, though." I know she'll probably chalk it up to her parenting and her tumultous marriage, and I can be honest with her and tell her that it played a small part in my aromanticism, but-- oh god idfk where I was going with this. She's going to blame my aromanticism on a lot of things, so I'm still trying to figure out how I'm going to come out to her in a way that won't make her start hating herself (if anyone has advice on this, I'm all ears).
In the meantime, we're okay. She trusts me and respects my counsel despite the age gap and hierarchy. Trusts me way too much, actually, so I hope it stays that way even when I come out.