Galpal Cheated on Halderman With Dave

The story of David Letterman’s twisted love triangle with alleged extortionist Robert Halderman continues to unfold. Former Late Show staffer Stephanie Birkitt was still sleeping with Letterman even after moving in with Halderman—and as late as last fall Birkitt and Letterman went hiking together, sources tell the New York Post. Birkitt—whom Letterman offered a job as his personal lawyer last year—told Halderman she was simply Letterman’s “best friend.”

Though Halderman and Birkitt stayed together until last month, sources say things began to fall apart when he read her diary—and learned of her continuing affair with Letterman—in December. He allegedly began his extortion scheme by dropping off a screenplay outline about a talk-show host brought down by an affair in Letterman’s limousine, prosecutors say.