I've been with my partner 6 years - not married, no kids, no desire for either.
We are both self employed, but he earns around three times what I do per year (I think about £70k) He has about £80k in savings and investments (as far as I know, he doesn't share exact figures) and I have less than £2k.
We have no mortgage, but I am repaying a loan each month that I took so I could buy a small share in the house we own (my partner owns the vast majority) We split all household and food bills in half.
I'm really struggling at the moment with cashflow, as I've had a slow couple of months with work, despite doing all I can to improve things, and I'm going to have to use savings or credit cards to top up my income until things even out again - which they will, probably in autumn (so this won't be an ongoing issue.)
I have spoken to him about this, and although he was sympathetic, he didn't offer any financial help, which I know he could easily afford - for example, to pay all (or more) of the bills for a couple of months. If the roles were reversed I would absolutely offer to pay for more things - in fact I did, earlier in our relationship, when he was in a less well paid job.
On the one hand, I see that my situation isn't his problem, I'm a grown woman and I should support myself - on the other, I feel like we're supposed to be a partnership but there's a real sense of what's his is his. My previous partner had much less money but was incredibly generous and would have given me his last pound, and it makes me sad that my current partner wouldn't even think to offer.
YABU - you shouldn't expect your partner to pay more
YANBU - it would be reasonable for him to offer to help for a couple of months