Demi and Ashton just happened to be on the same flight coming home from a conference, which is a little awkward if seeing famous exes together makes you feel awkward.
But things got REALLY uncomfortable when the cameraman starts asking about spousal support.
But Demi and Ashton keep it cool and continue to discuss protons or neutrons or computer chips or sandwiches or whatever it is they were discussing.
And then Demi walks away without even turning her head to bid farewell to her former lover.
So Ashton just waves and says, "Bye, Demi," and your lip starts to quiver a bit.
Then he keeps walking and probably reflecting on his past life (this GIF is in slow-mo for a dramatic effect).
And Demi went her separate way and the world didn't implode and it turns out exes can be friendly toward each other even if they are celebrities!
