Why is it all fun things are considered evil? Without oral, I think life would be very dull!
Most likely, it is considered evil because religious texts say so. Think about it, if all we did was oral, we'd have no kids, there'd be no next generation to pack out the churches/synagogues/temples etc. Religious leaders have a vested interest in keeping people procreating!

And as for Shakira's arse, lemme attit!