Is LeAnn Rimes cheating?

Sources told Us Weekly that Rimes, who married former backup dancer Dean Sheremet seven years ago when she was just 19, has been sneaking around with Cibrian since filming their Lifetime flick Northern Lights, set to air March 21, 2009.

Cibrian wed model Brandi Glanville in 2001. The couple has two children ages five and 23 months.

"From the moment we rehearsed, LeAnn and Eddie honestly developed a really strong bond and a warm relationship," says Mike Robe, director of the Lifetime movie.

Rimes and Cibrian were busted by security cameras that caught the pair holding hands and kissing during a date at Mosun and Club M in Laguna Beach, CA in early March. Us Weekly is also reporting that the couple shared a three-hour tryst at the Malibu Beach Inn the following week.

Rimes was just confirmed to be the 2009 recipient of the Academy of Country Music/The Home Depot Humanitarian Award, honoring country music artists that serve others and have a "generous spirit." Generous in bed counts.

Cibrian's manager refused comment. Rimes' rep said only, "We do not comment on our clients' personal lives."

But Rimes has commented on her website. She wrote, "This is a difficult time for me and my loved ones, but I appreciate all your continued support. I would like to assure all of you that this is a place for you to hear things directly from me and as you all know, not everything in our lives is always black and white."

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