when you have a caffenated drink or or snack in your mouth then you make-out with someone who has done the same. idea comes from how birds feed there young.
dude, i was just chilling there with my redbull and then out of no where this chick just fucking tongues me while she had mt dew in her mouth. love birdsex
by snipeman September 3, 2012
Get the birdsex mug.