This sexual act is a variant form of "sploshing", a term which may be more familiar to the British, and the British alone (or perhaps the extremely obscure sexual groups present in the more rural regions of America, as well).
Although there is no definitive record of the first act of this nature, it can be inferred that this act was first performed during the great American circus era at the turn of the 19th century. Today, this sexual act may most-likely be seen in today's fetish pornography, or the more extreme humorous pornographic material which is prominent in todays 21st century adult entertainment.
Midget Animal Handler: Really!? What did she say?
Clown: Oh, she obliged of course! So I pulled out of the vagina, grabbed a cream pie, came on it, and hit her in the face with the pie! All in one smooth motion.
Midget Animal Handler: Get outta here! How did she react!? What did she say?
Clown: She said 'What in the fuck was that!?', and I said "...a Big-top Creampie!" Then I honked my bicycle horn twice."