Justin Guarini ‘secretly dated’ Kelly Clarkson

Kelly Clarkson’s fellow ‘American Idol’ finalist Justin Guarini claims they had a secret relationship.

The ‘Because of You’ hitmaker – who is expecting her first child with husband Brandon Blackstock – won the first series of the show in 2002, and the runner-up claims they began a romance when they starred together in movie ‘From Justin to Kelly’ but separated when her career grew more successful while his stalled.

According to a review posted on website Mcall.com, Justin told the audience at his ‘Lovesick’ one-man cabaret show in Pennsylvania last week about the romance, and also with another ‘Idol’ contestant from his series, the fourth-placed Tamara Gray.

Justin – who has two children with wife Reina – has previously described Kelly as being ”like a sister” to him.

He also said in 2012: ”We’ve just always been such good friends. Um, man, it was weird; she was like my sister on the show, and then you know, we made a movie together. … I’d say, we had a good time. Yeah.”

And speaking around the release of ‘From Justin to Kelly’, the ‘Stronger’ singer was quick to dispel talk of a romance with her co-star.

Kelly insisted at the time: ”We’re like brother and sister.”