When the guys are invited to a university fundraiser, Sheldon is the only one who doesn't want to go.
- Anything That Moves: After sleeping with Leonard, Professor Plimpton tries to have a threesome with Raj and Howard; when Leonard shows up, she calls for a foursome.
- Did You Just Have Sex?: Penny picks up on Leonard and Elizabeth's body language and figures out they slept together.
- Ethical Slut: Elizabeth is a Nice Girl and an accomplished scientist that Really Gets Around and is not ashamed of it.
- Extreme Libido: Elizabeth seems to be something of a nymphomaniac. Despite being invited by Sheldon to visit Caltech, she seems far more interested in seducing his friends and having sex. And according to Leonard's comments she's pretty good at it too.
- Genius Ditz: Elizabeth is a genius on her field but comes off as weird even to some of the guys.
Elizabeth: Ah, Dr. Cooper, thank goodness. I completely forgot your address. But then I remembered that I'd written it on my hand. Lucky for me, I didn't confuse it with what I'd written on my other hand, which are the coordinates for a newly discovered neutron star. 'Cause if I tried to go there, I'd be crushed by hypergravity.
- Fanboy: Sheldon is one for Elizabeth's work, which is why he invites her to Caltech.
- Girl of the Week: Dr. Elizabeth Plimpton is a scientist who visits the guys at Sheldon's invitation and ends up sleeping with both Leonard and Raj, and tries to seduce Howard.
- Hands Go Down: When Elizabeth wants to have a foursome with Raj, Leonard, and Howard and the guys are considering it.
Leonard: Show of hands, who actually wants to do this?
[Howard raises his hand]
Leonard: We'd all be naked. In front of each other.
[Howard lowers his hand]
- Home Nudist: Elizabeth confesses to Leonard she wrote her famous book, The Effervescent Universe, while completely naked.
- Hot Scientist: Elizabeth (Judy Greer) is a very attractive the world-famous cosmological physicist and author.
- Put on a Bus: Bernadette. Howard only mentions to Raj that they broke up weeks ago; it is later revealed the reason why they broke up in "The Hot Troll Deviation"
- Sexy Discretion Shot: Elizabeth drops her robe in front of Leonardo who stares at her dumbfounded. Cue Fade to Black.
- Slut-Shaming: When Penny finds out about how Elizabeth Really Gets Around she nicknames her "Dr. Slut Bunny".
- Toplessness from the Back: Elizabeth has her bare back to the camera when she strips naked in front of Leonard.