You starve a wild mongoose for 5 days and 4 nights in your bathroom. On the 5th night walk in on it and try to ejaculate on its face.

The phenomenon of having to come out as bisexual to the same person/people repeatedly because they assumed or hoped that your sexuality was a "phase." Refers less to the holiday and more to the 1993 Bill Murray comedy film in which the main character experiences the same day over and over.