Proclaiming her "the biggest star in the world" and that "I love the woman in a way you can't on television," David Letterman welcomed Julia Roberts onto "Late Show" Tuesday night. What he didn't do was ask her about her recently ended relationship with Benjamin Bratt (they were together nearly four years). Instead, during the monologue, Letterman suggested that his bandleader, Paul Shaffer, pop the personal question to the "Erin Brockovich" Oscar winner. So, came time for Roberts, 33, to appear, she was primed to face the query -- which Shaffer indelicately presented as, "You getting laid these days?" The audience roared, the censor didn't bleep it, and Julia jumped behind Dave's back for protection, shaking a finger at Shaffer and saying (with mock seriousness), "Bad, bad Paul." Later, when Letterman mentioned Bratt by name, Roberts, speaking publicly for the first time on the subject, responded, "It's come to a kind and tenderhearted end. My only regret is that the media can't accept that it's tenderhearted and kind." Once she dismissed the widespread rumors that she's been going out with George Clooney, Roberts said, "I love Benjamin. He's a good man, he's a fine man. He is, to the exultation of the female single population, not my man anymore." She said the break was "not ugly (and) not because of anyone else." They both have simply gone "separate ways." Finally closing the book on the subject, she said, "And to answer Paul: No.' "