Joke about taxi and drunk

3 drunk guys entered a taxi. The taxi driver knew that they were drunk so he started the engine & turned it off again. Then said, "We have reached your destination". The 1st guy gave him money & the 2nd guy said "Thank you". The 3rd guy slapped the driver. The driver was shocked thinking the 3rd drunk knew what he did. But then he asked "What was that for?". The 3rd guy replied, "Control your speed next time, you nearly killed us!"