AITA for being openly resentful of how differently my sibling and I spend our parents’ money?

Since I was a kid, for some reason I learnt to be frugal with my parents’ money. We come from a country/culture where kids can’t work, so my first paying job was once I was in uni, and depended on my parents till then. They still pay for both of our tuition, and I am grateful and intend to pay them back.

My sibling (S) is 2 years younger than me. In high school I noticed that S was being more frivolous with spending money for hangouts with friends, telling my parents only after spending it. Meanwhile I was against my friends’ ideas unless they were cheap, because the few times I had asked my parents, they had rarely said yes. My parents support both of us completely for uni. I went far away from home, and travel home is expensive. I strived to save every penny, even if my parents suggest taking it a little easier. I worked part time during my second year, and supported my parents by covering my rent and other expenses.

My parents ended up going with S to S’s uni at first. S’s uni was relatively closer, but much costlier. The difference was based on our different courses (engineering vs finance). I was already jealous, but it was understandable because during my time covid would not have let them join me anyways.

However, I was annoyed when S basically begged to visit home only 4 months later for S’s first 2 week break, cuz S was homesick, and all friends had also gone home. My parents gave in because they missed having their kids home too. I understood at the time, because even I was homesick, but sucked it up because I didn’t want to put that load on my parents. Part of me was glad my sister could get that support.

However, I do see S being more frivolous in in their uni country through social media. I know S has a fixed monthly budget, so I guess it’s fair. I don’t have a budget, I get an annual amount that I use to make ends meet. I save so I never have problems, and I never check how much more or less it is than S’s budget. Apparently finding a part time job was hard there, so S couldn’t do that till recently either. What ended happening afterwards is that S would come home every 4 months (2 weeks in dec, and 3 months in the summer), while they could only afford my 4 months in the summer (because I don’t push to come back in dec). I can’t ask them to bring me in Dec because the difference in tickets is huge, and I can’t ask them not to bring S.

• Anytime I bring up how often S gets to come home, my parents get sad, and S mentions the ticket prices. I try to bring up the difference in tuition, but by then I feel bad for my parents hearing about all this.

I don’t resent anyone, and I am grateful for what I have in this world, it just hurts to feel that anything I do to save and help my parents, is in vain, because that surplus goes to whatever my sister does anyways. When I say I should also start being frivolous, my family jokes about us going broke if both the kids are like that.