So, here is something you might have missed from today's Justice League trailer earlier. In fact, I completely missed it too, but this tweet from @ pointed out my blatant error.
It appears that The Flash has a taste for Rick and Morty as you can see it playing on one of his screens in the trailer. A screen Ben Affleck's Bruce Wayne is standing in front of.
Take a look:
So there you have it, here is a pub quiz bit of trivia for you. Batman has (will?) appeared on screen with Rick and Morty. Fun!