Actor Blake Lively’s four-year-old nephew accidentally caught her in the buff as she was getting ready for The Late Show With David Letterman, last week. “He came running in and I said, ‘No, no, don’t come in, I’m naked...’ but it was a little too late... He sees me, turns beet red and folds over laughing,” contactmusic.com quoted Blake, 24, as saying. “I didn’t know if I was embarrassed or flattered. He couldn’t get it together,” she added.