Alice and Bob go into this bar. It's late at night and they're drunk. They get a drink each and go off into their corner. They start gettinging a bit frisky, and kissing and canoodleing. The barman isn't too happy, but seeing as they're such good customers, he lets it slide. Before too long, though, they're both naked, and getting down to it.

The barman covers his eyes, trying not to look. As he sneaks a glimpse through his fingers, he sees something wierd - he can't make out what they're doing. He looks again, but is still confused. He turns to the drunk propping up the bar next to him, and asks, "What's going on? He seems to be screwing her over the table AND getting a blowjob at the same time. That doesn't make any sense. Looks brilliant though, doesn't it?"

"Yeh," sighs the drunk whistfully, "It's a super position."