As LeAnn Rimes and Eddie Cibrian went public with their relationship in August, her ex Dean Sheremet quietly reached out to Cibrian’s ex Brandi Glanville, Us Weekly reports in its latest issue.

“They have been supporting each other,” an insider said of the pair, who first met last fall while visiting their spouses on the Calgary set of the Lifetime romance Northern Light.

At the time, they didn’t know an affair had begun. Now, the source tells Us Weekly, “They’ve put the pieces together about the last few months, and they’re developing a good friendship through this.”

Adds a Sheremet pal, “They’re the ones who understand what the other is feeling.”

How is Sheremet, 28, feeling? Friends tell Us Weekly he’s struggling. On Tuesday, Rimes announced on her website that she and Sheremet are divorcing — days after taking a PDA-packed vacation with Cibrian, 36, to Cabo San Lucas, Mexico, to celebrate her 27th birthday.

Asked how it feels to see his ex with Cibrian, Sheremet fought back tears before telling Us Weekly: “I don’t really know what to say. It’s bizarre. It’s surreal. But I’m doing OK.”