Just as The Sopranos ended with a metaphor for uncertainty, and so maintained the possibility of both Tony Soprano’s death and a life spent in fear, so must the question of Mario’s penis remain uncertain. Those pornographers that frame his penis so questionably are getting at the essence of the matter in a way Super Hornio Bros., giggling all the way, never will: the penis must remain a question to be answered only by the viewer, or the player. If the very purpose of a Mario game is a symbiosis with its star; if he is the synecdoche of the player, his movements laser-guided to be what that player wants them to be; if his fundamental goodness is intended as a belief in the goodness and courage within all people—then the existence of his penis only matters insomuch as it does to the body of the player.
In all seriousness, I think it’s clear Mario would have a penis, (i.e. an embodied sexuality) in canonical Nintendospace, the abstract world in which Mario exists, but that it would not exist in Nintendoanschauung, the view of that creation to which Nintendo consents.