Katy Perry and John Mayer sent the rumor mill into overdrive when Katy emerged from the couple's Valentine's Day dinner at Vincenti Restaurant in Los Angeles sporting a heart-shaped ruby ring on her left hand.

But the two singers are not heading down the aisle, according to People magazine.

A source tells the magazine that despite the ring, the couple is "not engaged."  The ruby ring with a gold band was made by Daniel Gibbings, a jeweler and designer from Santa Barbara, California, which is Katy's hometown. John picked it out all by himself, a rep for Gibbings tells People, noting that the singer was "really super nice" while