I must admit my fiance and I have a far less... sophisticated... system for dealing with bills.
"Did a bill come today?"
"Yeah."
"You want to cover it or me?"
"Doesn't matter."
*bill floats from desk to couch to fridge over a period of days*
"Have we paid this?"
"Oh shit!"
And then it gets paid.
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Nah, usually we just split everything 50/50, circumstances providing. Money really isn't too much of an issue between us, thankfully. We both hate the idea of not pulling our weight - we even fight over who GETS to pay a bill sometimes.