We have no rules on the coffeepot, unless one of us remembers to ask the other or does it ourselves.
Every now and then (about once every 2 weeks or so) Onyxx will set it up to brew. And about twice that often, husband will set it up. Mostly though it's me.
Of course, I drink more coffee than anyone else. So I guess it's kind of fair...
And the messes? husband shakes, sloshes coffee on the counter or floor (or occasionally the wall) and doesn't notice. Since Onyxx came home, this happens less - I think she's wiping it up before I see it. I threatened to get him a sippy cup...