Meg Ryan Wants to Warn Ex John Mellencamp's New Girlfriend That He's 'Poison': Source

Meg Ryan wants to save another woman from going through heartbreak at the hands of John Mellencamp.

The actress' on-off romance with the rocker — which ultimately ended for good in 2019 — was quite the rollercoaster, which is why an insider claimed she wants to reach out and let his new girlfriend of roughly eight months, Kristin Kehrberg, know he's not worth the trouble.

"Meg believes John is poison to any woman and will only make Kristin miserable in the end," the source spilled to a news publication. "She's trying to get the message to her about what she's in for."

"John may pour on the charm in the beginning — but he's selfish to the bone," the source added. "Sooner or later he will slide back to his bad habits, like neglecting to call, forgetting birthdays and showing up late — or not at all."

The Sleepless in Seattle lead, 61, and Grammy winner, 71, hit it off in 2011 but split in 2014. By 2017, the exes reunited and became engaged the following year, only to call it off in 2019.

"Meg felt John could never settle down — and his active dating life since then has borne out her fears," another source explained, referring to the multiple women he romanced after Ryan but before the socialite, which includee beauty guru Jamie Sherrill, realtor Natasha Barrett and skincare expert Marianelly Agosto.

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"Meg wants to open Kristin's eyes to John's bad boy ways and tell her things will go sour," the first insider said. "It's inevitable!"

Funny enough, the "Jack and Diane" crooner recently admitted in an interview that he didn't treat his ex-fiancée the way she deserved.

"I love Meg Ryan. I went with her for ten years," he shared. "She doesn’t love me so much. She’s a great girl. I’m just a s----- boyfriend."

Meanwhile, the mom-of-two now has "her heart set on meeting someone who isn’t part of the whole Hollywood scene," an additional insider said of Ryan, who has also romanced Dennis Quaid and Russell Crowe.