Oops. The studio behind "Heredity" is laughing off a case of mistaken trailer play in Perth, Western Australia.

Apparently a projectionist accidentally played the trailer for the R-rated horror movie before "Peter Rabbit," confusing and upsetting the families expecting PG entertainment.

The trailer for the Toni Collette horror movie -- plugged as "this generation's The Exorcist" -- included "scenes of scissors being pinched into a dead pigeon's neck, a corpse laid out in a coffin, a boy bloodily smashing his head into a desk and a man on fire, all set to tense music and sharp sound effects."

So not what the parents had in mind for their kids. Here's what one woman told the Sydney Morning Herald:

"It was dreadful. Very quickly you could tell this was not a kid's film. Parents were yelling at the projectionist to stop, covering their kids' eyes and ears. A few went out to get a staff member but she was overwhelmed and didn't really know what to do. Some parents fled the cinema with their kids in tow. Eventually a senior staff member came in with a walkie talkie and he shut the screen off. To his credit he apologised and offered us complimentary movie passes to make up for it."

Fled the cinema! If this was the trailer they saw, it takes a while before it gets really dark:Well, A24 -- the studio behind "Heredity" -- had some fun with the incident and even mocked "Peter Rabbit" for its controversial food allergy bullying scene:

Shots fired. Poor Peter Rabbit. That movie's studio apologized for the food allergy scene. "Peter Rabbit" is coming out on Blu-ray/DVD here in the States next week. Meanwhile, "Heredity" just got some extra publicity before it opens in theaters on June 8.

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