Heavyweights - The 'Torn' Shirt
Fast Forward to the part in the movie where the fat kids are getting revenge, and they kidnap Lars then proceed to tie him to a tree. The fat kids then put honey (or something) on his chest, and then rip his shirt down the front. Watch for a little longer and you will go back to the scene where the goat is licking the honey off Lars' chest, and...wa hey! The shirt is not ripped anymore! Wait till the next scene, and presto chango, the shirt is ripped again.
The Movie Heavyweights