How to Eat Fried Worms
(2006)

Billy (Luke Benward) wins the bet when he gets to eat his 10th. worm shortly before the deadline - OR SO IT SEEMS!!- .  It turns out that, back in Adam's (Austin Rogers's) uncle's café, Billy didn't get to eat the 2nd. worm, because it was taken inside an omelet that Principal Burdock (James Rebhorn) had for breakfast, while Adam was "cooking" the worm; so Billy only had nine in total.

However, he decides to share the agreed punishment with bully Joe (Adam Hicks), and they both walk around the school's main hall with a large amount of worms inside their pants.

Thanks Dr Mat!