One would think the set of a Lifetime TV movie was the last bastion of fidelity, but no. Country singer LeAnn Rimes was caught having an affair with married costar Eddie Cibrian while working on their new flick. Us Weekly touts the affair on its new cover, complete with surveillance footage that shows the two kissing while on a dinner date. Rimes, 26, married dancer Dean Sheremet when she was 19 years-old, while Cibrian—best known for appearances on Ugly Betty and Samantha Who?—has two children with model Brandi Glanville. Meanwhile, the country chanteuse has taken to her Web site to respond to the damning cover, saying, "This is a difficult time for me and my loved ones, but I appreciate all your continued support," and that "not everything in our lives is always black and white."