folks were confused, so I am hereby filling everybody in on a new industry term: Smurfing.  No, not like gerbilin' at all and nothing to do with Papa Smurf and Smurfette or spinners or blue balls... LOL.

Here is the definition from a great site that covers such topics:
www.sexdictionary.com

smurf - v.
Slapping someone in the face with your penis.

Notice that it is a verb.  I think the term originated in England... not sure, but I have seen some pretty funny definitions of it.  Old timers call it "d&ck good ol' slappin'".  I think it was made famous by Marilynn Chambers or Annie Sprinkle... can't quite remember.