Well done, matt. I have to say it's essentially the same joke as the one I know, but it's only about a quarter of the length, so it's a good job they asked you rather than me!
rab]Lisa is on a very sticky wicket as she has to make an immediate impression with the public and the housemates. She has certainly rattled their cages and under Cameroon's skin, and she will almost certainly be up for eviction next week, hopefully up against Cammeroon. If that were the case he should go, to build the tension further between the remaining players. But nothing really can rescue this series.
A linguistics professor was lecturing to his class one day. "In English" he said, "a double negative forms a positive. In some languages, such as Russian, a double negative is still a negative. However, there is no language wherein a double positive can form a negative."
A voice from the back of the room piped up, "Yeah, right."