How do you split costs when living with a partner who owns the home?

My partner (31F) and I (34M) are moving in together after 2.5 years of dating. We’re serious — talking about engagement, kids, etc. We're both attorneys, but come from very different financial backgrounds. She grew up affluent and is debt-free thanks to family support. I grew up low-income but got full scholarships through all my schooling. I still carry about $140k in debt from school living expenses.

She owns the home we’ll be living in (3 bedroom 2 bath with a mortgage ~$1,700/month). Her dad is currently covering all of her expenses as she is unemployed due to Trump firings. He has the means to do this, quite literally, indefinitely. It's just a matter of if he will. All signs currently suggest he will until at least December 2025. Afterwards, if needed, I can cover all our expenses.

I just started a nonprofit job earning ~$110k. I’m happy to contribute and we’ve discussed splitting bills 50/50 including car insurance (I drive her SUV about once a month to visit my parents and top off the gas when I'm back). I would be added to the car insurance policy when it renews.

The sticking point is rent/mortgage. Some people I've spoken to say its "inequitable" for me to be paying into a home that I gain no equity in (we're both pro-prenups) especially given our wealth disparities including familial wealth disparities. Others think I should just do 50/50. We will certainly draft a leasing agreement with a break whenever and no penalty clause in case of break up.

I looked online and have seen a bunch of different ways people have handled this:

• Straight forward 50/50 (with the caveat that the non-owning partner does not pay for major home expenses -- new refrigerator, painting walls, if the heater goes out, AC, etc.)
• Some form of "equitable rent" on a sliding scale based on incomes or based on the fact that one partner owns the home. So maybe paying 60/40.
• Partner who doesn't own the home doesn't pay "rent" but pays all utilities (some argue this removes potential "negative" feelings of paying into a home they don't own). Interestingly, I've found this often in heterosexual relationships in which the man owns the property but woman does not, which I find fascinating. I rarely saw it in the reverse in my limited research.

At the same time, paying $850/month to live in a 3bd/2ba in DC (Eckington/NOMA) is a steal compared to market rates where I'd be paying $2,000 for a 1 bedroom. In this way, I'm still not gaining equity in the home I'm paying half the mortgage of but I am saving considerably against the normal rental market.

Curious how others have approached this kind of situation. What worked for you? Ultimately, the objective is just to pursue whatever feels best for us such that no one feels there's anything "unfair." But I am interested in seeing if there are other creative agreements we might not have come across or thought of.