I know you probablly all know this...but they do say that man's eternal fascination with the/any anus stems from his deep-seated freudian feelings of inferiority/inability at being unable to 'create' - like the opposite sex. That's why men are, apparently, also fascinated with poo.
I know all guys say this, but I too am a total ass-freak. Whenever the ref isn't looking, I've always got one finger off-side..
My gf finally let me try it for the first time recently. It just aint gonna happen again. I would love to think otherwise, but it aint...