Nick Lachey has slammed his reality show Newlyweds: NICK + JESSICA as a "dumb idea", insisting it was partly responsible for breaking up his marriage to Jessica Simpson. Lachey appeared on The Late Show With David Letterman on Wednesday (12OCT06) and the talk show host quizzed him about the demise of his marriage. Letterman said he thought taping the show would actually make the marriage stronger to which Lachey replied, "About that. Not so much. "I don't think so... it was among the dumber ideas I think I've ever seen executed in history." Lachey claimed it seemed like a good idea at the time: "For a while, I think we actually enjoyed doing the show as well. It was just so invasive that it became a problem." When Letterman asked if the show contributed to the split he said, "You know that's one of those things where I think until you get enough hindsight and enough clarity and perspective, I don't think you can really know what happened. But, I certainly think it was probably a factor." The WHAT'S LEFT OF ME star insists is still friendly with his ex-wife, adding, "I think both of us have handled it about as well as we possibly could, under the microscope that we're under and everything. "But, I think, again, with time, it'll give us a better opportunity to redefine our relationship."