A man joined a fire department and after his first day, he came home and told his wife that from then on they would run the house like the fire department - by the bells.

He said" When I walk thru the door at night I will go DING.  That means to get my drink, pipe and paper and bring it to my easy chair where I will relax for a while.  
When I am done relaxing, I will go DING-DING.  That means to go up stairs and get undressed.  When I start up stairs, I will
go DING-DING DING.  That means get on the bed and spread your legs. I want some sex."

Well the next night, it went as he asked.  However, after three bells and as he was pumping away, his wife goes "DING-DING DING-DING."  He immediately stops and demands "What in the HELL is four bells?" His wife replies " Roll out more hose or get closer to the fire"