Isn't that a rather self defeating question? Assuming the orifice didn't have teeth that wanted to do me any harm, I'd fuck that until the cows came home and then I'd eat the cows, you know, cuz that's how I roll.
For all your new sexual orifice needs I suggest you read the 120 Days of Sodom by the Marquis de Sade... Lots of new orifice exploration in that one... Definitely not for the faint of heart.