Tropes in The Big Bang Theory Season Three
- Emotional Regression: Sheldon becomes like a child with Leonard and Penny as his parents in multiple instances.
- Hypocrite: in The Jiminy Conjecture Raj is about to call Sheldon out because it was inappropriate to talk about Leonard and Penny's "just fine" sex in front of them. Even though the conversation only went in that direction because Raj and Howard were making fun of it themselves.
- The "I Love You" Stigma: Leonard saying it first and caught Penny off guard, leading into their break-up.
- Relationship Upgrade: Leonard and Penny, technically made official at the end of the second episode.
- "Shut Up" Kiss: Penny is ready to date Leonard but he still doesn't know when to shut up, she helps him out there.
- Sitcom Arch-Nemesis: The beginning of Sheldon and Wil Wheaton's rivalry.
- Sore Loser: Sheldon, when he loses the game to "WHEAAAATOOOOOOOON!!!!"
- Their First Time: And it was weird.