Robert Pattinson on Ellen -- FIRST LOOK!

Robert Pattinson happily tells Ellen DeGeneres about his underwear mishap on the Breaking Dawn set during the taping for his appearance on The Ellen DeGeneres Show.

The 24-year-old actor shared with the host, “I don’t know how to use a washing machine [either], so I save your ones [the "Ellen" underwear] for special occasions.”

Rob continued, “They very rarely get brought out. I was doing the last Twilight movie and I only had one pair left and they were those ones. We were doing this big fight screen and for some reason I think the shape of my body, my back is too long or something. So my a– is constantly hanging out (laughs).”

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