My partner (27f) and I (25m) are currently not dating anyone else

3 years ago we were originally polyamorous but she is mostly asexual / demisexual and introverted so I was the main one dating. We're discussing reopening again later this year

Anyhow, she makes minimum wage, has no family support, and lives paycheck to paycheck.

Since I have known her she has never had spending money for events more than once in a blue moon. She doesn't drive, and every dollar goes to rent, food, and bills. She's had some terrible roommate experiences and refuses to live with anyone but partners again

I don't make much more but I'm lucky enough to have lower expenses and a roommate. Because of this I pay for everything we do. I pay for every meal, every concert, every movie ticket, every gallon of gas and so on

I used to take her to more events, but the financial toll of buying double concert tickets, dinner, drinks etc and so on wore on me and I started going to more things alone.

She's a little upset, but pretty understanding of this. I still take her out often to cheaper alternatives

The issue is in the past I would have other partners invite me to do things like weekend getaways, camping, concerts, fancier dinners, etc and it was more feasible because we could split the bill 50/50

My partner would get upset because of me agreeing to do things like this with other partners, but not as often with her. She also likes to be "first" in every new experience

This is one of the reasons we closed our relationship. Because I had poor boundaries, codependency, and didn't like upsetting her all the time

I'm reluctant to move in with her for financial reasons because we have other issues that need to be solved first. I also like my own space and would like to be able to host other partners eventually

She's very sweet and not a bad person, but I'm just worried if we open our relationship again we'll continue to have these issues around mixed finances and me preferring events with partners who can pitch in

TL;DR

My partner has 0 spending money. She gets upset if I choose to do things with other partners instead because they can pitch in 50/50 compared to our 100/0

How to navigate this?