Something along the lines of "don't ever go to bed angry at each other." Like, yeah, you should try to work it out, but if you fucked up real bad, don't push it. Sleep on the couch.
Never send an angry email the same day, and always send it to someone else for reviews. Also never put the recipients in the box until you're ready to hit send.
Besides couch is superior to bed, those nights when I can't get sleep in the bed the couch provides. Couch best. Even the cushions are for some reason nicer than pillows. Should definitely consider moving to the livingroom.