I was just walking back to the office with two of my male co-workers. As we passed the ladies toilets one of them 'checked out' a woman as she went in. He was promptly chastised:

"You just broke the golden rule, never check out a girl when she's going into the loos."

"Why?" replied my other co-worker (and I wondered too, was it some kind of chivalry perhaps?)

"Cos you know she's full of piss."