The Big Bang Theory, Season 5

[Sheldon and Amy are talking in her apartment]

Sheldon:
I was hoping she [Penny] might listen to you about the dangers of owning unhygienic furniture.

Amy:
For general educational purposes or has she acquired a bar stool dipped in cholera?

Sheldon:
Cholera is water-borne, you're mocking me.

Amy:
Yes, I am.

Sheldon:
Penny has dragged a chair in off the street whose unknown provenance jeopardizes the health and welfare of every resident of our building.

Amy:
Sheldon, just because you have a focus on cleanliness bordering on the psychotic doesn't mean I have to participate.

Sheldon:
Alright. Name your price.

Amy:
[thinks] Kiss me where I've never been kissed before.

Sheldon:
...You mean like Salt Lake City?