The act of ejaculating on a persons face, and before they have the opportunity to clean up, throw a handful of birdseed at their face. The ejaculate will cause the bird seed to stick, much like a pine cone bird feeder.

Briefly, "the realization that each random passerby is living a life as vivid and complex as your own." Originally from the Dictionary of Obscure Sorrows, which has a lot more beautiful neologism definitions like this you might enjoy.