Cooking with someone is to encounter the division of self and other. It's even more acute, I think, than stepping into another's home. In another's cooking I can't avoid that each has their own habits, anxieties, superstitions, and turn-ons. It would seem logical to suggest that infatuation softens the perception of another's culinary peculiarities, but actually I think those peculiarities are among the most difficult to sop up with a romantic narrative. Sexy food movies have it all wrong; the kitchen is not where you fall in love, but where love is strained. It's where pet peeves exert their strongest impulse, and you're forced to realize that the other is a person, and that you might also be one. Or maybe it's just me.
For the same reason, if one is inclined toward psychological or anthropologic curiosity, the way another cooks is an object of fascination. The most interesting discoveries are made, as in those two fields, when one's position as an observer is most compromised. When you discover that those slices of onion are too large, that blenders are not used that way, that no not a big on salt, that hashbrowns must have the liquid squeezed from them before fried, that you must not mix anything together before everything is measured and ready, that certain ingredients are equivalent, that shrimp must be veined or you must burn in hell, etc.