A reference from the game Portal, all through the game you are told their's cake at the end. Once you get there -SPOILERS- there is no cake :( so it was a lie. This became a saying amongst gamers when something doesn't go as planed.
You try to capture a flag but there's a enemy camping there you didn't see before and he kills you.
Also spelt 'moomy cake'
Common term relating to the breasts of a lactating male.
The milky man-teats are seen as a very sexual and prominent part of the male body, with females biologically attracted males who lactate from their nipples.
Featured in the recently leaked Black Eyed Peas hit song "Moomie Cakes"