Ace Young and Diana DeGarmo Ace Young and Diana DeGarmo

American Idol alums Ace Young (Season 5) and Diana DeGarmo (Season 3 runner-up) are opening up about their relationship — after keeping under it wraps almost two years.

"We became best friends through Hair, ironically not through Idol," DeGarmo tells People. The couple met on the set of the Broadway show in the spring 2010, but parted ways after the musical closed that June.

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Young, 31, returned to Los Angeles, while DeGarmo, 24, went on tour with the musical 9 to 5

. "If you love somebody, whenever they're not around, it sucks," says Young.Shortly after her tour ended, DeGarmo headed to L.A. and has been living with Young ever since. They've even a formed a band together, called All Access.

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"She's my best friend," he says. "To be able to dive in with Diana and help create songs that [tell] her story is amazing."