'AITA for refusing to share any of the $10k my grandpa gave me with my little sister?'

"AITA for refusing to give any of the $10,000 my grandpa gave me to my younger sister?"

I (18M) recently graduated from high school. A couple of weeks after graduation, my grandfather invited me on a weekend trip to his place on the East Coast. For context, my grandfather is extremely wealthy — he used to work on Wall Street as a stockbroker and now he’s a venture capitalist.

The trip was amazing. He drove us out there in his Rolls-Royce, and he has a very nice villa by the water. We went sailing on his yacht, ate at some nice restaurants, and watched movies. It was honestly a great bonding experience overall. On the last day, he surprised me with a $10,000 gift for graduating and getting into college.

I was shocked and super grateful. I thanked him, must've been at least 100,000 times on the way home and told him I’d be putting it toward college expenses. He liked that idea.

However when I got back home and told my mom about the gift, I expected her to be happy or at least say “Wow, that’s amazing!” Instead, she said, “I think you should give it to your younger sister. I think she needs it.”

Now, my younger sister (16F) is, quite frankly, the most spoiled brat I've ever met in my entire life. She gets ANYTHING she wants whenever she wants it. Besides being spoiled, my sister is genuinely a HORRIBLE person. She's had two boyfriends, both of which she cheated on and both of which she manipulated into thinking it was their fault.

She lies to my parents about getting drunk, lies to my parents about how much she spends on alcohol, lies to my parents about smoking weed (even though its obvious), damaged her car while driving drunk, stole money from my parents, stole money from me and let HER FRIENDS drive MY CAR, and my parents car, multiple times.

Despite all this, my parents never punish her. She’s also failing most of her classes, does nothing around the house, and either sits in her room all day doomscrolling and smokes weed, or goes out getting absolutely hammered with her friends.

So when my mom said that, I was livid. I told her that my sister didn’t deserve any of the money and that I’d need that money in college. I also added that my sister would probably just blow it on alcohol or other substances. My mom fired back that all college kids waste money on booze and that my sister could really use it for her studies and gas money. To reiterate, she’s basically failing every class.

Later that night, my mom sent me a long text suggesting a compromise; that I give my sister half of the money. She argued that $10,000 is “a lot for one person” and I’d still have $5,000 left. I said absolutely not, my sister hasn’t done anything to deserve it. I reiterated that she’s constantly lying and being irresponsible and I’m not rewarding that.

Now since this whole thing my sister’s been acting slightly better. She’ll do a chore here and there, and she offered to drive me somewhere last week (which she's never done before). but I think it’s all an act because she knows about the money now.

My mom thinks I’m being selfish and greedy, and keeps telling me I “don’t know how to manage money anyway.”, and that her compromise is entirely fair. But I genuinely think it would be wrong to give her any of it.

So, AITA for refusing to give my sister any of the $10,000?

What do you think? AITA? This is what commenters had to say:

UsualSuspect1369 said:

NTA but your mom is.

And since your first response was to use it for college, obviously you are responsible with money.

bdayqueen said:

NTA - Tell your mom that you're sure your Grandpa will give your sister some money when she graduates, so she should work on that. Put your money in a bank account that your family can't access.

Shiel009 said:

NTA- OP, a lot of times banks might require a co-signer on a checking/savings account. Ask to see if your grandpa will cosign an account that a credit union (they generally don’t have monthly fees) and put the money in there. If you put it in account y that your mom help create, then she can legally take the money

OP responded:

Thanks for the advice. My grandpa was actually the one to drive me back, and he helped me open a separate account at a local credit union with my himself as the joint account holder. The account is solely in our names, so my mom can’t touch it. I made sure it’s a no-fee student account with limited withdrawal access just to be safe.

Jumpy-Speaker8517 said:

Why would you give your graduation present from your grandpa to you spoiled sister and your mother is an AH as well

And BigRedJeeper said:

It is YOUR money. Not your mothers and certainly NOT your sisters. If your grandpa wanted to give her $$, he would have. Maybe if she straightens up and graduates he might give her some.

This was a gift for graduating high school. How dare your mom try to guilt you Ii to giving her anything!! You mom is a total ass, not you. I’d open a ban account that your parents have no access to ASAP and deposit it before it’s gone!!

He later shared this edit in response to commenters:

To all the people telling me to move the money to a new account, when my grandpa drove me back home, he helped me open a separate account at a local credit union with me and himself as the joint account holders.

The account is solely in our names, and I made sure it’s a no-fee student account with limited withdrawal access just to be safe. And to the people worried about my mother stealing the money, she's not that deranged. She’s definitely pushy about the money, but she's not at all the type to steal it.