Matt Lauer creepily whispered to Meredith Vieira ... "Keep bending over like that. It's a nice view" -- and it happened on set, while cameras were rolling.
This all went down in October 2006, and it's a little bizarre how it got out to the public. The show had gone to commercial, but in at least one city, the local affiliate stayed on NBC's in-studio feed. Matt was seen sitting on the couch as Meredith got mic'd up.