Jack Spratt had convenient relationship with his wife in regards to eating meat. Apparently he couldn't eat any fat and his wife was unable to eat "lean". I think this relationship is convenient as the rhyme says they are "unable" to eat fat or lean.
In our house the relationship is slightly more stressed as Heather criticises my sweeping up skills, (when I can be bothered to give it a go) but she is unable to actually put the piles of dust, breakfast cereal and small assorted pieces of plastic in the bin. This leaves me to come into the dining room and see the offending collection of mess in a neat pile on the floor, find the dustpan and put it in the bin (I don't swear often, but I am tempted to stray at this time). Or not see the pile and kick it across the floor again.
We have discussed this situation with each other and decided that we should carry on being married, even though the relationship does not seem to be as easy as Jack's and his missus. But there again, perhaps Jack does all the cleaning in his house, he is obviously the fitter of the two.
I think I may have started something here???!!!