Her smile may melt hearts but Julia Roberts used it as her secret weapon as she grilled the talk show host, coercing him with her million-dollar smile to dish on marital life.
Watch Roberts and Letterman's love fest in the above video.
"Did she take your name?" Roberts, who was on the show to promote her new spokesperson role of Paul Newman's foundation Hole in the Wall.
"Yes," Letterman replied.
"So she's Mrs. Letterman?" Roberts pushed.
"No, she's Dave," he answered causing the actress to burst into laughter and give a dig to Letterman's new time slot competition Conan O'Brien.
Roberts added: "You're so much funnier than other people at this time." Oh, snap!