9 Movie Extras Who Completely Ruined Their Scenes

7. North By NorthWest Spoiler Alert!

A long-time favourite since it combines the two things that make the internet great - cuteness and head-numbing idiocy.

Directors everywhere should learn from this little lad's scene-spoiling self-preservation as he anticipates ear-offending gunshots - quite simply, if you're looking for an authentic reaction from an untrained child, you should probably try and keep it to one shot, because the crafty little devils will spoil the impact of the scene by preparing themselves for a shot the audience doesn't know is coming.

Hitchcock probably loved this, and included it for fun in the final edit (you have to suspect he wouldn't have missed it accidentally), but that doesn't avoid the fact that the little fella destroyed the magic of the moment.