A bloke was visiting the World Trade Fair when he spied a machine rather like a drinks disperser. He saw a man go up to it. He stood right against the machine, having unzipped his flies, pressed the knob, wriggled about a bit and then gave a sigh:-
"Aaaaa, that's better!"
A couple of minutes later another fellow came and did the same thing,
"Aaaaa, That's better!"
The bloke decided to give the machine a try. He unzipped his flies and got out his prick, held himself close to the machine.