Sheldon: So are you and Leonard still not having coitus?
Penny: Do you have to say coitus? Can't you just say we aren't seeing each other?
Sheldon: No, because that wouldn't be true. You and Leonard still technically see each other all the time.
Penny: Still, I'd prefer if you wouldn't use that word.
Sheldon: "Well, all right. I'll just substitute intercourse."
Penny: "Great."
Sheldon: "...or fornication...but that has judgmental overtones so I'll hold that in reserve."
Penny: "Fine."
Sheldon: "Just to be clear, do I have to stop saying coitus with everyone or just you?"
Penny: "Ummmm...everyone."
Sheldon: "Harsh terms but all right."
Penny: "Naaah! I'm just coitusing with ya!"
(simulated dialog from the Big Bang Theory when I laughed my gluteus maximus off)