There were 2 men working in a haulage yard. One of the men was moaning that he had not had sex in over a year. The other man said "when its quiet go over to one of the lorries where the exhaust is still warm and pop your self in it, its just like being in the real thing."

That night the man went over to where the lorries were kept and did what he was advise and was filled with immense pleasure. The man started to do it on a regular basis, but noticed one day  that he was starting to swell.

So the man went to the doctor and had some tests. The doctor came back and said, "im sorry its bad news your HGV positive."