@SMW83,
Put it in writing.
This is not in anticipation of breaking up. Rather, it's so everyone is clear on what's expected of them.
Your fellow agrees to pay:
- £200 per month for groceries
- £400 per month for his living space (you can get an idea of cost by looking at typical rents in the area and then giving him a discount of at least 25%)
- £100 per month for utilities (and then list the utilities: landline phone, cable TV, gas, oil, electricity, trash removal, water, heat, whatever is paid as utilities in your area)
- X amount for groceries if you share them.
- He agrees to pay for expenses that are solely his, such as his own phone, any meals out he has without you, his own clothes and his own personal care products (assuming you don't share these).
Of course substitute the correct numbers for my own.
If he balks and says it's too much, well, he just stopped having to pay full rent for an apartment. And keep the cash in a separate account and don't touch it. It doesn't have to formally be escrow but treat it that way. Call it a rainy day fund or vacation fund or a wedding fund or whatever you like.
If you break up, give him, say, 25% of it back. After all, if you break up, he'll lose his home. If you stay together, then use it for whatever big expense you like and call it a day.
Reassess in a year. If you get a more permanent connection, then you might be able to ditch this. But right now, it's in everyone's best interests to have this stuff in writing and stick to it.
You're his landlord (or landlady). Just because you sleep with him doesn't mean he isn't costing you extra utility or grocery money.