He’s tight, he’s selfish, and you shouldn’t be in a relationship with him, especially when you have children with someone else.
What happens if you have kids together? He’ll create a scenario where the children are unequal.
Yes, in an ideal world you go halves. However, when there is financial asymmetry, that’s not realistic.
So that means you either do things that the lower earners can easily afford, or the higher earner treats when they want to do an expensive activity the lower earner would have difficulty doing.
After 2 years this should not be an issue.
The fact he’s moaning about car-hire after you spent more than twice the amount he did tells you what kind of guy he is.
When DH and I first met we earned the same, but I was living independently and paying off debts whilst he lived at home. He paid for loads of things without EVER making it a big deal.
We’re now both good earners and treats go back and forth without thought.
You’re a fool if you stay with him.