Are our finances unreasonable?

This was works for you and that’s fine. You have lot of money so don’t have that massive money stress hanging over you in the way that lots of people do. Because money or the lack of it isn’t a stressor in your life you can be more free with it. You’re very lucky. If money is a big stressor, as it can be for many, and the source of arguments, because let’s face it, not having enough money is incredibly stressful, you’re more likely to want to keep a track and keep things “fair”.

If it works for you both, then I see no reason to change it.

My DH and I are a bit like this, albeit it has evolved over the years (we have children too so that’s a major additional expense).

The one sticking point we haven’t quite worked out the answer to is ‘planning for the future vs ‘spending today’. It’s quite difficult to plan for the longer term when you have no idea what your collective financial position is…!

I'm always surprised to hear about people in high paying jobs without strong critical thinking skills, empathy or dare I say much common sense!

Sounds fine. We don’t do it that way because we’re in a completely different situation.

Like others have said, you currently have the luxury of not needing to worry about 'fairness' or running out of money. That's quite rare.

Other people need to budget or monitor who pays for what because otherwise, essential bills don't get paid, there's nothing left for annual and irregular expenses like Christmas, holidays, car repairs etc or someone is missing out due to their partner's spending choices, eg DW can't replace her only bra, which is falling apart, while DH has daily coffees, Pret lunches and a fully funded golf/cycling/motorsport hobby.

You've already identified the disparity in your pension arrangements, which could be offset by your DPs inheritance, which he says he's going to put into the house you buy, but you need to think about what things will look like when you're retirement age and his income drops massively or if you split up and he wants to take back the money he put into the house.

That might mean one or both of you do start to care about who pays for what. For example, what pension arrangements does he have and could/should he be saving more. How would you feel at retirement age if he has little or no pension but wants to continue spending money on 'stuff' that he can no longer afford?

More power to you, OP; that just sounds like two people working as a team rather than a pair of business associates conducting transactions and keeping score.

My other half and I are pretty much the same - although I earn about three times as much, we just don't care even though we keep separate accounts (I used to have a gambling problem a couple of decades back so it was the safest option, and it just kinda stuck because it works). If one's short, the other covers it...usually me, but it doesn't really matter. After all, who wants to see their partner struggle?

The only thing we've made absolutely sure of is the accounting for the house; it's strictly 50-50, but that was only to keep my in-laws at bay.

We've lived through real struggles, we've had times when we didn't know how we were going to heat the house...so now that we've got plenty of money, we just appreciate it for what it represents: the removal of a source of stress, so that we can live happier lives. Any suggestion that we should re-introduce that stress by keeping score seems bonkers to me.

I disagree. We are in a similar position and also have a young child.

We’re slightly older than OP and have been together for around 20 years.

We’ve never had a joint account for anything. We’ve also never had a single argument about money.

We don’t really budget other than putting huge chunks into pensions each month. We’d also have no idea who has spent what or if it’s anywhere near 50/50 over the last 2 decades. I don’t think either of us care to be honest.

When you’re rolling in money it is easy to look down on those who need to budget and track expenses/shares to make ends meet.

I would still advise doing a budget of some sort and ensuring you are saving for your future non working old age,

I'm on the other side of the fence than most of MN. I don't get the idea of even having separate accounts. If you are together, then be together. You're a family, not flatmates! Doesn't matter who earns more or less, everything is pooled together and expenses are family expenses, not mine and his. Btw, i am the higher earner (by a lot) and still don't mind.
And yeah, I realize I am a minority and have different values than most on here. No wonder the divorce rate is so high. Nobody goes "all in" anymore, I guess.

I think it would matter to you if you were on a low wage. Sounds like with your salaries it’s just irrelevant

Sounds good, I’d get married though.

Because you both have lots of money to spare and no children
Throw in one of you not being able to work or having a child then it wouldnt work

Not unreasonable at all. I cant see how partners work it any other way. It does sound like you arent struggling at the moment though. It might be worth having a conversation about how you'd manage if you were.

YANBU - for now. It works fine as you are both high earners with no dependents.

But you do need to have a discussion about future plans - kids, house purchase etc.

Particularly if you have DC, which usually results in a salary change for the woman, as well as a whole series of new child-related costs, it’s really important to understand how money will be managed and allocated and be on the same page.