Actors John Krasinski and Billy Crudup engaged in a spirited olive-throwing contest Wednesday night at Cabin Down Under on the Lower East Side. Comfortably seated at the back bar, the pals let loose while Krasinski’s wife, Emily Blunt,went to the ladies’ room. Crudup was overheard egging on “The Office” star Krasinski, “No one throws olives any more.” Krasinski warmed to the challenge and picked a plump olive from his plate to chuck over the bar, our spy said. Crudup followed with a few more tosses, closing up the game just before Blunt returned.