Last night on The Tonight Show With Jimmy Fallon, Denis Leary revealed a riveting story about an encounter he had with Rod Stewart's lower half.

Leary explained that he had been hosting CBS' Fashion Rocks award show in 2008.

Stewart apparently helped himself to Leary's backstage dressing room.

When Leary entered the room he received a full-moon view of Stewart's rear end.

Within seconds the singer turned around and faced Leary giving him a frontal view.

Leary was then forced to return to the stage to introduce Stewart for his next performance.

In an embarrassing brain slip, Leary says in front of six thousand people, "Ladies and gentlemen, please welcome back to the stage, Cock Stewart."