The premise: Ant-Man helps himself to a Coke Mini from the office of Dr. Bruce Banner (that's the Incredible Hulk's alter-ego). "Hey Bruce, you don't mind if I just take this last coke, do ya? Thanks, bye!"
The punchline: He does mind, actually. The Hulk catches up quickly with the miniature superhero, who kindly opens up his struggling adversary's Coke can and gets a sip of his own while he's at it. "You have the greenest eyes," Ant-Man tells the Hulk.