You fuck one goat... or you fuck one sheep....
This is based on a well-known joke; here's one version
A big Scot is sitting in a bar, ranting as he downs his pints. He pounds his hand on the bar, says "You see this bar? I built this bar with me own two hands, a finer piece of work you'll newver find, but do they call me MacGregor the bar-builder? No!!" and he downs his pint and buys another.
He points out the window. "See that dock in the lake? I built that dock with me own hands, a finer piece of work you'll newver find, but do they call me MacGregor the dock-builder? No!!" and downs his pint.
He next pointed out the chair and table in the corner, the fence outside, all sorts of similar projects, and says "I built that with me own two hands, a finer piece of work you'll newver find, but do call me MacGregor the handyman? No!!"
He stares into his beer, whispers, "And you fuck one sheep."