Meg Ryan Desperately Trying to Warn Ex John Mellencamp's New Girlfriend to 'Open Her Eyes' to His 'Bad Boy Ways'

Rockstar John Mellencamp is said to be smitten with widow Kristin Kehrberg, but his ex-fiancée Meg Ryan wants to warn the socialite that she's going to get burned, RadarOnline.com has learned.

Sources dished that Ryan allegedly thought her former fiancé was "poison" to his romantic interests.

"Meg believes John is poison to any woman and will only make Kristin miserable in the end," an insider dished to the National Enquirer. "She's trying to get the message to her about what she's in for."

The You've Got Mail actress and Mellencamp had an on-again, off-again relationship before getting engaged in 2019, which was eventually called off less than a year later.

"John may pour on the charm in the beginning — but he's selfish to the bone," the source continued. "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."

Mellencamp revealed that he met his "beautiful" new love seven months ago and boasted about how his latest girl has "never" gotten mad at him.

Before the multimillionaire Manhattanite hooked up with the rock star, she was married to a famous advertising executive, Richard "Dick" Tarlow, who died in May 2022 at age 81.

The Hurts So Good singer's relationship with movie star Ryan ended in November 2019, the same year as their engagement. Since then, Mellencamp has dated beauty guru Jamie Sherrill, realtor Natasha Barrett, and skincare expert Marianelly Agosto.

Despite his active dating history, insiders alleged that Mellencamp was all the while still pinning for Ryan, even though she kicked him to the curb.

Sources went as far as claiming that the Sleepless in Seattle star moved to a new mansion in Montecito, California, which was complete with extra-tall gates to keep Mellencamp from dropping by on-the-fly.

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

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The insider's claim echoed comments from close pals who said Ryan had zero regrets about breaking her engagement to Mellencamp.

"Meg felt John could never settle down — and his active dating life since then has borne out her fears," a source told RadarOnline.com, as they noted the plethora of relationships Mellencamp was involved in since Ryan.

"[Meg] told him he's happier out on the road than he would ever be with her," the source added, while another claimed the rockstar really "tried really hard to make things work" with the actress.