Shit or get off the pot
"[...] or get off the pot" is a common English language expression, used to urge one to complete a task at hand with a greater degree of efficiency or timeliness than is observed at the time the expression is used.
It may derive from the time before indoor plumbing when a chamber pot was used at night. If someone had to go, and someone else was using the pot, this expression would have been appropriate for hastening the "slowpoke". Stuart Flexner, author of "I Hear America Talking", states that it is a vulgar rephrasing of the old New England expression "fish or cut bait."
Richard Nixon reportedly (Newsweek, 1984 April 16) used the phrase with Dwight Eisenhower in berating Eisenhower to put Nixon on his presidential ticket.
Chris O'Donnell used this phrase to propose marriage to his girl, wishing to accept his hand in the movie The Bachelor. He lost his bride.