First used in Mr. Natural Comix, circa 1968...the sound made when one ejaculates into another's mouth (in Mr. Natural's case, a Big
Baby). Similar to the classic
Batman onomotopoea's, such as "paff" "oof" or "spwack"...only, dirtier.
Blorp is indicative of not a thin, mealy stream of ejaculate, no...it suggests something grander, more substantial, like a massive snowball of
cum.
Consider the following dialogue:
Robin: "Mrrrphhh!"
Batman: "Oh, oh shit...I'm gonna
cum!"
*Blorp*
Robin: "Whillakers,
Batman, that was quite a Bat-load!"