An Abe Lincoln is when someone goes into the bathroom and pees on their hand, then proceeds to exit the bathroom and shake someone elses hand.
Person 1: Hey bro, gimme some skin.
( Person 1 and Person 2 do complicated secret hand shake).
Person 2: Ewww, why is your hand all wet?
Person 1: I JUST PULLED AN ABE LINCOLN ON YOU, SON!