When Sonny storms out of Connie's wedding to rough up the guy taking pictures of license plates, he has Paulie Gatto in tow, well behind him. After he spits on the FBI guy's credentials and says, "Goddam FBI don't respect nothin'," he and Paulie turn away. When Paulie is well distanced from the FBI guy, he makes a "cornudo"--the two fingered "horns" that are the classical Italian sign of the cuckold--but does it so surreptitiously that you barely notice it. A perfect sign of what a weasel he was, and a hint of treason to come.