Joaquin Phoenix's Letterman Appearance -- HUH?!

Joaquin Phoenix dropped by The Late Show With David Letterman on Thursday to promote his latest movie, Two Lovers.

The 34-year-old actor keeps his head down during most of the interview and doesn’t get very chatty. He even forgets his costar’s name — Gwyneth Paltrow!

In between the many awkward silences, Dave pokes fun at Joaquin‘s new look, asking, “What can you tell us about your days with the Unabomber?”

Joaquin does confirm he quit acting to pursue music. However, the audience does burst into laughter when he says he’s recording “more hip-hop music.”

Dave indirectly tells Joaquin it’s rude to chew gum during an interview. Joaquin then takes the gum out of his mouth and sticks it underneath Dave‘s desk!!! Dave ends the interview, saying, “Joaquin, I’m sorry you couldn’t be here tonight.”

Watch the must-see interview below. Two Lovers opens in theaters TOMORROW!