Count this as another example of why you shouldn’t mix business and pleasure.

Ex-Bon Jovi guitarist Richie Sambora allegedly is being investigated for threatening to kill former business partner and lover Nikki Lund, reports the UK’s Daily Mail.

The 55-year-old rocker is said to have threatened Kim Kardashian‘s childhood friend, 33, over the phone on March 19, which she reported to cops earlier this week.

“He said words to the effect that he was going to dig a hole in the desert and bury her,” a source told the publication.

According to the same source, fashion designer Lund had hoped the situation would resolve itself, but after it didn’t, she reported the threats to detectives at the Lost Hills Sheriff Station in Calabasas, Calif., on Wednesday night.

Sambora and Lund have been in an on-again, off-again relationship since 2006. They founded the fashion line Nikki Rich together, though the business fell apart in recent months as the romance also went downhill.

In December, she said her now-former flame was “amazing in bed.”

The rocker’s threats are said to have been made the day after Lund’s first signature solo show at LA Fashion Week on March 18.

According to the Daily Mail, the investigation may have to wait, as Sambora is believed to be on vacation in Bora Bora with ex-wife Heather Locklear and their daughter, Ava.

The investigating detective was not immediately available to comment.

Page Six was unable to reach a rep for Sambora.

This story first appeared in the NY Post.