Me and DP have been together for 3½ years. We do not have children together but DP has one child from a previous relationship. I love them both very much.
At the start of the relationship we discussed marriage, and we both agreed it wasn't something we'd ever want, despite being fully committed to each other and considering each other as life partners (neither of use are religious and we're both kind of non-conformist and were not motivated by the tradition).
Recently DP changed her mind on this and has now become adamant that she wants to get married and have completely joint finances, and she will leave me otherwise.
This puts me in quite an uncomfortable situation because of our respective financial situations.
I have had a lucrative but very high stress career. I'm not a particularly money motivated person and have lived frugally all my life. I'm now in a position where I am planning to retire within the next 5-10 years. I have a NW of roughly £1.5M. DP has a good job and earns quite well (very proud of her) but she only has savings of around 70K. And I do out-earn her currently by around 4X.
I've agreed to the marriage on the condition that premarital assets should be off the table if we ever ended up divorcing (of course you don't plan for it, but you never know).
I have no issue with joint finance and sharing all income going forward. That would mean me contributing 3-4X what she would, and that would be "our" money forever no matter what happens (split 50/50 if we separated). All income, pension, inheritance, or whatever else, shared completely from the point of marriage.
For "my" (i.e. the premarital) money, I consider it to be "ours" for as long as we are together. Anything she needs, or her DC needs, she'll have it. If we need a bigger house, I'll pay for it. My only condition is that if she ever leaves me, she doesn't get to take half of it with her. Only in that sense, it's still "mine".
I consider this a pretty good deal for DP. If we stay together as planned, she'd be able to retire in her 50s and we could travel the world together. Even in the unfortunate scenario that we were to split up after a few years, she'd still have done very well out of it financially and be in a good position to do whatever she'd want to do next in life.
But this is not satisfactory for DP. She insists that true commitment means "sharing everything" and that all premarital assets need to be split 50/50 in divorce.
My issue with this is that the "financial commitment" that she sees as being so important, is almost exclusively coming from me. There's no commitment from her because there's no risk for her. She'd end up rich (relative to where she is now) whatever happened. I'd be in a position where I'd lose so much by leaving, but she would lose nothing by leaving.
This doesn't seem fair, or balanced, or equitable, to me. Even disregarding my obvious self interests, it just seems to to be a really bad foundation for a relationship, because of the inevitable power imbalance it would cause.
I think DP should also be considering my needs and security, and be open to an arrangement which benefits us both as a couple and as individuals, without exposing me (and only me) to such risk. If roles were reversed, I'd want to protect my partner so that they could feel completely secure in the relationship.
So my answer is "no", and now she's leaving me.
She thinks I'm "more sacred of losing my money than of losing her". She thinks I'm being overly analytical and "treating it like a business deal". She says I shouldn't even be thinking about it as losing "my" money, because it's all "our" money anyway. She says she'd rather be alone for the rest of her life than be with someone who won't share everything with her.
So, AIBU?