“There are like one of three people who know how it ends, and I’m one of them,” teased newest Gossip Girl cast member Lydia Hearst of tonight’s finale. Sitting backstage at the Life Ball in Vienna, Hearst was surprisingly secretive for a girl wearing sequined, tasseled pasties. “I can’t say anything, but it’s so good. And the clothes are gorgeous.” Hearst has a lot of inside info on Gossip Girl: “My best friend in the world is on the show, Michelle Trachtenberg,” who plays evil bitch Georgina Sparks. “It’s kind of scary how good she is at that role. I’ve known Ed for forever, and Chace and I have gotten close too.” Reeeeally. We wonder how close. Not to start any new rumors or anything. Hearst is only just recovering from the one that started over the weekend, which suggested the 24-year-old was being, well, intimate with model Marcus Schenkenberg. “Ugh, my mom read that!” she shrieked. “He’s like, nice, but old enough to be my father.” Actually, he’s only 40 … “No, no, no!,” Hearst protested. —Kendall Herbst