Entertainment Movies Paul Rudd Is a Sponge-Carrying Member of the David Letterman Fan Club The Ant-Man star has held on to his membership kit for more than 30 years By Lindsay Kimble Lindsay Kimble Lindsay Kimble is a Senior Digital News Editor and the Sports Editor for PEOPLE Digital. She's worked at PEOPLE for over seven years as a writer, reporter and editor across our Entertainment, Lifestyle and News teams, covering everything from the Super Bowl to the Met Gala. She's been nominated for the ASME NEXT Awards for Journalists Under 30, and previously wrote for Us Weekly while on staff at Wenner Media. People Editorial Guidelines Published on April 22, 2015 11:20 AM Share Tweet Pin Email Paul Rudd is a total fanboy – for David Letterman. During an appearance on Late Show with David Letterman, Rudd, 46, proudly admitted to his three-decade membership in the Letterman fan club. “About 30 years ago, when you first started the show, back when the [Kansas City] Royals were in the World Series, I joined the David Letterman fan club,” Rudd said. The Ant-Man star confessed he doubted the authenticity of the club, which Letterman said they had to issue a cease-and-desist order against. Rudd still enjoyed the perks of his membership, though: “What it included was a pin, a collapsible drinking cup, a sponge that – if you put in water – would grow, a back scratcher and a balloon,” he said. The actor held on to his yellow pin, proudly wearing it during his appearance, as well as the expandable sponge. “Finally, now, three-fourths of my life later, we should see what happens,” he joked, as they watched the lackluster sponge work its magic in a bowl of water. Letterman, 68, ends his tenure as host of CBS’s Late Show on May 20. Stephen Colbert will take over hosting duties after Letterman’s departure. Late Show with David Letterman airs weeknights (11:35 p.m. ET) on CBS. RELATED: Will Smith Gets ‘Jiggy With It’ on Late Show