Both middle aged. Not living together, but spend a lot of time together and spend a lot of time a the "homeowners" house, sleepover 3-4 eves a week. Roughly equal salaries. I mean covering costs at the homeowners house, as well as paying for trips and dinner etc.
Partner one:
Owns own home mortgage free, adult DC, comfortable, as there is passive as well as earned income.
Partner two:
Rents, no DC. In many ways a more difficult life, with some setbacks meaning "starting over" a couple of times. Has enough to live comfortably, but not for the same lifestyle as Partner one, if all costs are shared.
Partner 1 is wary of being taken advantage of and of protecting assets for DC. Partner 2 likes to pay their way, but that restricts what is affordable.