Heheh. That's a nice twist on the fairy tale. I think the detailed descriptions of the penises probably warrant an R rating. It's also a good companion piece for your story set in a tavern in Angband.
Author's Response: Thankies, Ria! Glad you enjoyed it. Hmm... in Australia it would probably get a recommended 15+ (not restricted 15+), which is why I gave it a PG-13. We don't have things higher than R in Australia (X is illegal) so R is pretty extreme. I will bump it up, though. :) Thank you very much for the heads up.