The Bells

A fireman tells his bride that he wants sex when he comes home from the firehouse.  "When I shout One Bell, it means get undressed. Two Bells, get in bed.  Three Bells, spread your legs."

A few days later, he comes home to test his system.

"One Bell!" he yells, and his wife strips.

"Two Bells!" he yells, and his wife hops in bed.

"Three Bells!" he yells, and her legs part for him.

A few minuted into the lovemaking and suddenly his wife yells out, "Four Bells!"

"What the hell is Four Bells?!" the fireman snorts.

"It means I need more hose."