Simpson, sometimes known as "Yoko Romo" because some Cowboys fans think she's bad luck and a distraction to Romo, defended her presence at Cowboys games.
"I don't believe that I was a jinx, but everybody is being so paranoid about those superstitions," Simpson said.
They then turned to the players' equipment, and Simpson brought something a bit odd up: "I don't think they wear cups," Simpson said of NFL players. "Do you know about that? I know they were a jock strap, but that's not a cup, is it?"
Letterman said he's pretty sure NFL players do wear cups, but after the commercial break, Letterman said he checked and acknowledged that he was wrong and Simpson was right: Many NFL players don't wear cups on the field.
Part two of the interview is after the jump.