This thread reminds me of my ex-h. He earned 2.5 times what I did, and everything was still split 50/50 - mortgage, bills, holidays etc etc. My salary would go into the bank, and by the time I'd paid my half of everything, I was almost skint within a few days of being paid. He would occasionally lend me money for petrol, which would go on a tab, and I'd have to pay him back next payday, but this just meant I was even more skint - a downward spiral.
I once asked my Dad for petrol money, he obliged, but has since said he was horrified my ex was so mean. Sometimes my ex would get into a real strop if I couldn't afford to go out for a meal; this meant we wouldn't go out, even though he could easily afford to pay for me.
He had it all worked out though; if we had a child (we didn't, thankfully), I'd go back to work ASAP (maternity pay wouldn't cover my share of the bills, even though he could afford the shortfall ...... ) and the child would be cared for, full time, by his mother, who was in the mid-stages of dementia, and couldn't tell the difference between a baby and a toaster ......
It's not hard to see why we're no longer together!
My new husband and I pool our finances. And it works.