Endings should not melt into sticky grudges and shapeless self-pity. Endings should be as airy as molasses puffs, their memories as sharp and pleasant as bittersweet chocolate. But to guarantee civilized behavior, one requires civilized circumstances: a place where no one dares slap or cuss or rail; a place where the tiniest gulped sob sends one to the restroom for privacy and phlegm-spewing hysterics warrant a room upstairs. You arrange to meet at the Ritz. You order, you cross your legs, you converse. Your voice stays low and cultured; your mood is so contained that you start to believe you're OK. The Ultimate Chocolate Kiss martini makes it even easier to sustain the illusion. And if your confidence falters by the end of the ending, the doorman will open the heavy door for you, offer to fetch you a taxi and wish you a pleasant evening with such obvious sincerity that you believe him, too.
If the whole relationship was based on an illusion, you might as well end it the same way.