A customer came to the Bar in rush, and ordered a double martini. He gulped it with one swallow, put a five dollar bill on the bar, turned and walked out of the bar.
The bartender picked up the five dollar bill, and folded it carefully and tucked it in his vest pocket.
Just at the moment he looked up, and shockingly saw the boss standing in the doorway observing his game. Bartender's mind started working at lightning speed, he responded the situation, "Hi boss, did you see that fellow just now? Came in here, bought a double martini, gave me a five dollar tip, and rushed out without paying for his Martini."