a bannana spilt is when a man and woman are having sex and the gurl does a split (spliting her legs open and as far as dey can go open and lies down) on the mans or his "bannana"

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.