How to ask a complete stranger to have sex? Is it socially appropriate?

Well, I was bored and somehow (yes, somehow) in an unknown [mis]hap i landed on ehow.com. Being the immature perve I am, i searched “sex” hoping an ironic article explaining how to have sex would come up, instead there were other things, like this: http://www.ehow.com/how_2086945_have-sex-airplane.html

Read the article, its quite short, they explain to you how to do something illegal, but also suggest if you do not have a partner, find someone on the plane, how would YOU ask a COMPLETE stranger to have sex? I’m just guessing the lady would slap you, so I’m just wondering, how would you lay it out…?