The but-plug idea are great but for the rest of the character interpretation of the prince would just mess up the games story, I mean even if you want that then the whole story would have to be redesigned because there is a glaring inconsistency towards the prince's character it's clear to anyone who played it and actually read and understood the dialogue of the story that he:
*never touched or cheated on a woman
*is actually a virgin(until he met the monster of course)
*was not evil or abusive, just the really arrogant
*gets what he wants done with strength but never hurt innocent people, like with Nine for example
So that doesn't seem to fit the story.