Quote of the series (so far!) from Makosi to Craig: "If you agree to come on Big Brother you agree to show your willy!"
Though producers can't grasp this, it's quite clear from past series that HMs don't mind showering nude in front of the cameras - but don't like doing it infront of their housemates. At least give them the illusion of privacy!
An evil way to get around this problem would be simply to turn the hot water off if a HM doesn't shower nude!