It’s getting serious between Barbara Walters, 77, and Dr. Robert N. Butler, 80. Walters and Butler, a Pulitzer Prize-winning author and gerontologist, just got back from a weeklong romantic Caribbean getaway to St. Martin, friends say, and she is “happier than ever.” A freshly tanned Walters is expected to go back on “The View” where we hope she’ll gush all about her new man to the ladies.