Secretely Jerked off in the Back of the Uber

I was already late for my flight back from London to Hamburg - and then I also got a spontaneous erection when I was waiting for my Uber to the airport! It doesn’t go away by itself and I can't go through the security check with a boner... So I must probably jerk off in the car! I'm as quiet as possible in the back seat while I jerk my cock – and I lick up the cum completely at the end, so that the driver does not get suspicious ;) (English)