Greg is pissed that he was not invited to the stag night.
GUYS. WHAT IF. WHAT IF GREG WAS INVITED. AND HIS LITTLE, “YOU DIDN’T EVEN MAKE IT TO CLOSING TIME” JAB WAS BECAUSE HE WAS SUPPOSED TO MEET THEM AFTER HE GOT OFF WORK AND JUST AS HE WAS LEAVING THEY GOT HAULED INTO THE DRUNK TANK.