Delta Goodrem is one of the best friends a girl could have – especially for her fellow part-time LA-Australian celeb, Extra host Renee Bargh.
So it's no wonder insiders say Delta's a little worried her girl is getting too close for comfort with Scientology – a religion desperate for young, beautiful, celebrity poster faces.
In recent months, Renee, 32, has taken to Instagram to proudly proclaim her affection for two of the church's most well-known followers, Tom Cruise and John Travolta.
In a gushing Instagram post last week, Renee, pictured cuddling with John, wrote, "@johntravolta is the epitome of class and grace. He's charming, giving, authentic, and a true movie star."
This, combined with a Tom Cruise flirtfest during an interview last year, set off alarm bells for Delta, 34, who, along with her partner Matthew Copley, is keeping a close eye on Renee.
"Delta's been in LA long enough to see plenty of people sucked in by its weirdness and fame, and no matter how chummy John and Tom try to get with Renee, she'll do her darnedest to keep her away from them.
"Delta's pretty private and won't say much, but you can bet she's been fretting big time to Matt. Hopefully between the two of them they can keep Renee out of Scientology's clutches."
WATCH: Think fast! Delta Goodrem answers quick-fire questions. Story continues after video...
Meanwhile, Delta's relationship with Matthew is going from strength to strength.
The much-loved Voice coach and musician, 34, has been confiding to friends that she's head over heels and rumours are swirling that the couple are ready to start a family.
"The word is that Delta's decided to have a baby sooner than later, and she's totally committed to a long-term future with Matthew," shares our insider.
"It makes perfect sense that she and Matthew are ready to be parents, because they're all about intimacy and the simple things these days."