I just rewatched the entire series on Netflix, and something is bothering me. Its what Flash says at the end.
His last line is "these are the end times", delivered with a complete blank look on his face... What is he referring to?
Right before Flash says, "These are the end times," he sees Martian Manhunter call his wife. J'onn tells her he'll be back in time for dinner and that he loves her. That's what Flash is referring to. He's making a joke about the Martian Manhunter's new human life.