Yep, I'd have to agree with all of the above, plus it's definitely, for me, something to do with being in that quite rudimetary position.....like animals. We've probably been mating in that position for longer than any other....going back to when we were apes.....

__________________
"Time flies like an arrow -
Fruit flies like a banana"

M Y - N A U G H T Y - P I C T U R E S ! !