What's the worst experience you've had at the movies?

Went to go see Lego Ninjago Movie this evening and it was a nightmare with the little girl next to me talking and running around all through the film and her mother not only not doing anything about it but [i]encouraging[/i] her to do it. When I confronted her afterwards about it and told her off she had the gall to act like she was the victim in all of this. So annoying and such a terrible example to set to your kids.

In lieu of this, what bad movie experiences have you had with the terrible audiences?