Cutler and Cavallari announced their decision to split after 10 years together in a joint statement last April. Cavallari has since moved on with country singer Chase Rice, but a source tells ET that she's blocked Kramer on Instagram after she went on a date with Cutler because she had previously thought of Kramer as a friend.
"Jana and Jay did go out on a date in Nashville," the source says. "Kristin believed that her and Jana were friends and has blocked Jana on Instagram in response to this happening. Kristin is moving on and doing her own thing."
The source also claims, "Jay knew Kristin would find out about his and Jana's date and he is trying to make Kristin jealous and it's not going to work."
However, a second source tells ET that 37-year-old Kramer and 34-year-old Cavallari are not close.
"Jana has never thought of Kristin as a close friend and only as an acquaintance who she has met a few times," the source says.
Kramer's divorce from her ex-husband, Mike Caussin, was finalized in July. In her divorce filing, the country singer accused Caussin of "inappropriate marital conduct, irreconcilable differences and adultery." The exes share two kids together, 5-year-old daughter Jolie and 2-year-old son Jace.
As for Cavallari and 38-year-old Cutler, they share three kids together -- 9-year-old Camden, 7-year-old Jaxon and 5-year-old Saylor. Cutler recently opened up about dating again after their split.
"It's hard as hell, really," the former pro football player said during an episode of his Uncut With Jay Cutler podcast. "Meeting people is hard. I think finding out what people really want from you; I think that's probably an issue."
"I'm at a different phase of my life now with kids," he added. "Priorities have changed. It isn't just a purely selfish play by my part."
"They have hung out in Nashville and are having a good time together and getting to know each other," the source said. "Kristin is not in a rush to get into a serious relationship. She is doing her thing and enjoying herself. Kristin remains focused on her kids and being the best mom possible, as well as her businesses and work."