I will also ask him to purchase groceries and maybe even cook - this way I don't spend time and money on him.
Is he reliable enough to follow through on this?
I could see various things play out. (NOTE: May be projecting here. My sister pulled variations on these stunts during family dinners.)
1) I'm not feeling well. Can't cook. Have a great time!
2) I'm at the supermarket. Can you believe that they ran out of XYZ? Do you have something in the fridge?
3) I have everything BUT the one crucial ingredient. Can you go out and get some? I'm cooking.
I would make alternative plans just in case.