OK there was this fellow about 65ish, it was his birthday and he was already 5 years retired from the navy, he decided to wear his old uniform and go out to the pub to pay
a lady of the night for wow .... some sexual activity.

anyway after a few hours he find a girl and takes her home, and they are doing it doggy..... he is panting away... and he says to the lady.... how am i doing....... and she said about 3 knots....... now this retired sea captain was amazed , how can this lady know about speed like this.... and he stopped and looked at her and said.... how do you know this...... and she replied... your not hard, your not in, and your not getting your money back.

okay; but how would you know that he would have to pay for a girl to sit on his lap

and how would you know that ...

At 3 knots a caterpillar would overtake a woman walking at a fast clip.