I (22F, "L") live in the same house as my aunt (33F, "M"). This house was built decades ago by my late grandfather so his 9 children would always have a place to live. Right now, only my family of four (recovering from my parents’ extremely messy divorce) and my aunt live here. my family has lived here longer.

However, my aunt doesn’t live here full-time. She has a temporary job abroad and only comes home around 3 times a year. All her stuff is still here (clothes, car, motorcycle, TV, etc.), and she has her own section of the house, kind of like a mini-apartment (about 40 m²), with a living room, kitchen, dining area, and two bedrooms—one for her and one for her young son.

My family also has a similar-sized section. We clean our own space and the rest of the shared areas in the house, and we also cover minor maintenance costs ourselves. Bigger repairs are covered by all the siblings since the house is often used for family gatherings. We don't clean my aunt's space for a few reasons: she gets upset when we touch her stuff, and whenever she visits, she leaves a big mess, assuming we’ll clean up after her.

Now, here’s the issue. Three years into working abroad, my aunt asked me to please start her car and drive it once in a while, because her mechanic told her it would help avoid issues from being unused. I agreed and started doing that. She also said she’d send money for gas, but she never did.

At the time, my motorcycle broke down, so I asked her if I could use her car to go to work. She said yes. I only used it like that twice (totaling 4 days of round trips), and I made sure to return it with a full tank each time—even though when I first used it, it was only half full. I thought filling the tank was fair.

Fast forward to now. My aunt recently came back and was complaining about how her space is never ready when she arrives. Another aunt, “T”, suggested she should pay me to clean it. Aunt M immediately said, “Oh right, she should clean it, but without pay, because the payment is that I let her use my car—and she’ll get to keep using it.”

I immediately said: “I only used your car as a favor to you, because you asked me to drive it occasionally to avoid damage. When I asked to borrow it, it was because I figured it could be a win-win—I’d have transportation to work, and I’d still be doing you the favor of using your car. Plus, I filled the tank, which was running low. But I don’t need to use your car. Next time my bike breaks down, I’ll just take public transport. I’m not going to clean your space as ‘payment’ for a favor you asked me to do.”

Everyone went silent, so I thought it was settled. But later, in the family group chat, some relatives said I shouldn't have spoken to her that way because she’s older than me, and I benefit from living in the house my grandfather left and from using her car. I replied that I’m grateful to live here—which is why I clean the rest of the house and pay for small repairs—(I'm the one who cleans everything up after family gatherings) but I don’t think it’s fair that she expects me to “pay” her by cleaning her space when she’s the one who asked me to drive the car in the first place.

My mom said it’s my fault for trusting her again—apparently years ago, she took advantage of another favor I did for her, but I thought maybe she had changed. I’ve decided I’ll never do her another favor again. Still, I’m wondering—AITA for refusing to clean her space as “payment” for using her car?

Small clarification: Before all this, I never used her car. When I first started driving it, it was just short trips around the block. The only time I used it for personal reasons was those 4 days I went to work. As for the gas money she promised—she said she’d give it to me when she came back from abroad, but she never did. I’m not super mad about that because I chose to fill the tank myself.As some people who have houses like mine may know, cleaning them once a week doesn’t just mean sweeping a little — it also involves washing the dishes, thoroughly dusting, washing the sheets and all the utensils, since these houses tend to gather a lot of dust. On top of that, as I already mentioned, my aunt always leaves a real mess when she leaves.

So, AITA?

(English isn’t my first language, sorry for any mistakes.)