Blake Shelton and Gwen Stefani’s dating rumors made headlines last week. According to some reports, the recently divorced Shelton and Stefani were “all over each other” while another report said the claims were “completely untrue.” But, according to Life & Style magazine, one person has been deeply affected by the rumors -- Miranda Lambert.

The 31-year-old singer was “upset” that Shelton was dating Stefani, who filed for divorce from English musician and actor Gavin Rossdale last month, the magazine reported in its latest issue. An insider said that Shelton and Stefani rumored relationship was Lambert's “worst nightmare.” Lambert and Shelton divorced in late July after four years of marriage.

"She's heard about Gwen and Blake and she's really upset. Before Blake hooked up with Gwen, Miranda and Gwen were friendly. But her new relationship with Blake will definitely ruin any chance of them ever being close again,” the insider told the magazine. "She's always felt like she could never compete with Gwen ... This is her worst nightmare."

The source added that Shelton likes that Stefani has children -- something which the 39-year-old wanted from Lambert, according to the magazine.

"Miranda never wanted to have children with Blake, and he wanted kids very badly. Gwen is a doting mom who comes with children; that is enticing to him. He loves that she has kids," the insider reportedly said.

Although reports emerged that Shelton and Stefani sparked their romance on the sets of “The Voice,” a source told Gossip Cop that the dating rumors were false.