To Directly walk up to a person and angrily ram you erect penis in to their anus. Thus cauing both pain and surprise.
Croat stands alone in an alley
Serb: approachs from behind and pants' him while ramming his erect penis to the the croats anal cavity.
Croat: "Oh my fucking god what the shit is in my asshole?!"
Serb: "Eat it Croat, its my Serbian Handshake!!"