My DP and I are planning to move in together in September. His preference would have been for me to leave my flat (which I own) and to rent a house together but we have agreed that initially he will move into my flat and we will reassess after 6 months. I think this makes sense for both of us as it gives us flexibility if things go wrong between us (which I hope they won't!) but it was really my decision.
We have not yet had a discussion about how finances will work when he moves in. Obviously I am expecting that we will split gas/electricity/increased council tax. But I don't really know what to suggest on my fixed bills and on rent. I don't really mind if he pays me or not - I am comfortably off and my costs won't increase as a result of him moving in. I quite like the fact that my flat is mine and I can see that maybe he would resent contributing to my mortgage when it wasn't his choice to live in my flat. On the other hand, it doesn't seem quite right that I would pay all of our living costs, particularly given that he earns considerably more than me. Whilst I don't need the money, it would of course be helpful - occasionally he wants to have extravagant meals out etc., which I cannot comfortably afford (sometimes I rein him in and sometimes I accept his offers to pay). Would it be reasonable to ask him to contribute about half market rate? This is a lot less than he is paying in rent at the moment and would cover about a quarter of my mortgage each month. Or should I just leave it and assume that if things do work out we'll share finances anyway and if they don't then I am lucky to be secure in my flat and not have to move etc.?
I do of course appreciate that we are both very fortunate and that this is a nice problem to have but I would genuinely welcome views on what is reasonable here. I'm conscious this sounds a bit glass half empty - I do think things will work out between us but, having seen my DM go through a terrible divorce and suffer financially, I just want to make sure that I have thought about things in advance.