Last night on the Late Show with David Letterman, the late-night host made his millionth blunder with nomenclature — this time with Young Adult director “Ivan Reitman, Jr.†— but Charlize Theron didn’t let it slide. “I oughta slap you for that one. Just for him, JASON Reitman,†she said before delving into how her selection as the lead actress was really just a backhanded compliment. Plus: 40-year-old Jeremy Renner won’t be babysitting his 6-month-old brother, Theo. Nor is he sure if there will be more in the Renner clan because, well, “Papa’s still pimpin’â€; and Ralph Fiennes can’t stand the lead actor (himself) in his directorial debut of Coriolanus. Watch our compilation to see what you missed.