Remembering Seigfried, losing his battle with cancer and just months after Roy Horn’s passing. ET looks back at our time with the legendary Las Vegas performers. And, why J.Lo’s teaming up with Lady Gaga. Plus, major celebrity divorces. How Mary-Kate Olsen settled with her ex with a half-billion dollars at stake. And, why Dr. Dre could be spending millions more on his ex-wife. Then, Anne Hathaway dishes on her new movie “Locked Down” and revealing her mom hack.