In my MLP AU, Draconeverse, Accord is Discord's older brother. He and Cosmos end up getting along well- Very Well, and end up dating. They turn out to be a great duo- well great to each other, that is. Accord treats Cosmos like an absolute queen- his queen- and she LOVES it.

They do get married, making Chaos Family Reunions very awkward I'm sure- especially since Cosmos *did* try to kill Wulfy and Discord's kids.