For context, I (F 18) work a part time job alongside my studies and make around £150 a month. My sister (F 22) and the boyfriend (M 23) both have enough disposable income to buy a tent.

I have a 4 man tent that is big enough for me to stand up and move about it, I have had it for a year and have used it a handful of times. I plan to take a trip in the summer and use it for a couple of nights and have already booked in at a campsite.

The tent cost me £100 which was a big chunk of my wage.

My sister is very bad at taking care of things, she gets frustrated and takes it out of objects. I do not want my tent to get damaged as they don’t sell it anymore. So, when asked I said no. Both my parents have tried to guilt trip me into letting her borrow it, saying if it breaks they will get her to replace it. I really don’t want her to borrow it. I am already letting her borrow my camp bed, but it doesn’t fit in the tent they already have so they need mine.

Pls tell me if i’m the asshole for not letting them use it, and what you would do if you were me.

EDIT: I was told by my friend to add that the main reason why my parents are pressuring me is that we had an argument recently over her not paying me back for a meal and apparently I came off rude and mean. Additionally my sister and her boyfriend bought me a concert ticket for my birthday so they feel I owe her something. (my 18th birthday gift)