The Big Bang TheorySeries 3 Episode 15: The Large Hadron Collision
Leonard is invited to Switzerland on Valentine's Day to see the world's largest particle accelerator. Sheldon is gutted when Leonard asks Penny to go with him, as a Valentine's Day treat, instead of him. Sheldon tries to coerce the couple into letting him take Penny's place, will they relent?
- Holiday / Sitcom
- Original air date