1) A situation in which there are many woman, and very few men, present.
2) A large number of vagines, or buns, with an extreme shortage of peni, or sausages.
3) The opposite of a Sausage Fest.
Guy 1: This Maroon 5 concert is awesome! It's a total Bun Fest here!
Guy 2: You're still a faggot for going.