s04e09 — Funny Pants

Squidward gets a terrible migraine from Spongebob's continuous laughter, and he tells SpongeBob that if he doesn't stop, his bubble of laughter will burst and he will never be able to laugh again. SpongeBob thinks he has lost his laughter and starts crying nonstop. Tired of his crying, Squidward tells the truth and bursts his bubble of laughter, having fun at his joke. Spongebob gives him a piece of his bubble of laughter, and Squidward starts laughing like him because of it.

P.S. the series is creepy...