As I've mentioned I'll be moving in with BF soon. This is going to sound super-analytical and not at all romantic so bear with me!
We've been talking about expenses. If we were married and assets were in both names, I'd say we pay expenses based on income. I make a little more, so I'd pay a larger percentage of expenses. But at this point, the mortgage is in his name so he is the one building equity and he gets the tax benefits. Put those two concepts together, and I think a 50/50 split is fair. I'd pay half of the mortgage plus half utilities. I typically buy groceries, but he usually pays when we go out. We typically trade off on household items like cleaners and TP - just whoever happens to pick them up. But he doesn't want me to pay half of the expenses. He thinks I shouldn't have to pay that much, that it isn't fair. If he won't let me pay half of everything, I swear I'm hiring a maid.

We've been talking about it for ages but he doesn't want to commit the funds each month.
So how do or did you and your BF do it, before assets were in both names? Could this be an issue because I make more and he doesn't want to feel like I'm supporting him? He can certainly do it on his own - has been for decades before I showed up. From my perspective, I don't want to feel like a sponge - a gold-digging girlfriend that moved in to save some cash. (Note: The money I'm saving on my own mortgage, as soon as my house sells, will go in to my 401K, which would be "our" 401K at some point.) I haven't had a chance to ask him more pointedly about it. I was surprised when he said half is too much and wanted to have some more options in my head before I brought it up again.