Christie Brinkley Breaks Her Silence on Relationship with John Cougar Mellencamp

— -- Christie Brinkley and John Cougar Mellencamp were first photographed together in September and it appears they're still a couple.

However, the supermodel told Howard Stern on Monday that she's "leery" of revealing too much about their relationship.

"I don't want to jinx it," she told the Sirius XM radio host.

Stern was in a unique position to ask. The radio host said that he introduced Brinkley, 61, to Mellencamp, 63, and encouraged her to convince the rocker to quit smoking.

"He has to," Brinkley agreed. "The voice is already made and he has to stop."

Brinkley and Stern also discussed her penchant for musicians. (She was famously married to Billy Joel for nearly a decade.) Artists, she explained are "the most amazing people because... they're constantly creating beauty for the world."

"I respect artists so much," she said, "and I absolutely love music as the ultimate art."