For 15 years, radio hosts-turned-TV stars Kyle Sandilands and Jackie O Henderson have dominated the airwaves with their successful and headline-making Kyle & Jackie O Show.
But it seems cracks are starting to appear between the once unshakeable duo, with on-air tantrums and simmering tension sparking rumours of an imminent rift.
Speaking exclusively to Woman's Day, a top TV insider reveals the pair could soon be heading their separate ways as small-screen projects cause a divide between them.
"It has to be a sore spot for Kyle... Jackie becoming a TV darling while his show bombed!" Quips the source, who notes the ill-fated Trial By Kyle was quietly dumped by Ten this year.
"Jackie's venture onto The Masked Singer [also on Ten] has her in hot demand. One day their radio show will come to an end and where does that leave Kyle?"
"He can be unpalatable without her by his side," muses the source, who insists the shock jock, 49, would be "anxious" his co-host's promising solo TV career could leave him "high and dry."
Now, says the insider, tensions at KIIS FM HQ are fast reaching breaking point...
There are few radio personalities who can boast a little black book like Kyle and Jackie, who are known for fostering friendships with some of the world's biggest celebrities – including Kris Jenner.
But could Kyle's temper ruin their access to the big talent?
Last week, the Sydney local had a tantrum on air after songstress Kylie Minogue was late to dial in, following a mix-up of times with her management.
"Where is Kylie Minogue is what I'm asking! How many times do I have to ask?" Kyle demanded.
"Where is the publicist from? What company?" He quizzed an embarrassed producer, who had to remind the hothead he was on air.
"I don't give a s--t who's listening," he erupted.
"Do you know how many people are waiting to hear Kylie? Get her on," he continued, before the PR company sent the station a prerecorded apology explaining there had been a miscommunication.
He's known for his crass and insensitive sense of humour, but Kyle also sunk to a new low last week when he quizzed model Jennifer Hawkins about her sex life.
The mother-of-one was stunned when he turned a discussion about breastfeeding into a vulgar chat about men sucking on their wives' breasts for pleasure.
As Jen and Jackie discussed their issues with mastitis (inflammation of the breast tissue), Kyle interjected with, "Wasn't that because the ex-husband was sucking on it before the baby was sucking on it?" in reference to Jackie's ex-husband Lee Henderson.
Meanwhile, things appeared to have become too much at the KIIS FM HQ when the show's producers recently announced they were going on "strike" and were refusing to assist the pair at all.
The decision came after Kyle called them "useless", adding that he and Jackie, 45, would "do the entire show producer free."
Meanwhile, Jackie has ruffled feathers with her staff after she launched a rant at one of her long-standing producers.
In a light-hearted segment, the pair asked producers who they "preferred", before Jackie blasted Sonia for choosing Kyle.
"What the f---, you're supposed to be one of my good friends, why would you say Kyle?" she said, then threatened to stop socialising with Sonia outside of work.
Not much is off limits for the radio stars, who are adored by fans for their prying questions and candid personal confessions.
But an interview with singer Amy Shark last week saw Kyle go as far as to suggest Jackie once had a cocaine addiction because of her "caved-in nose."
Jackie quickly confirmed she'd "never taken the drug in her whole life" and said the popular rumour Kyle had echoed was baseless.
"[It happened] because I got really skinny," she explained, adding that it was started by a "few people in [the] industry who were desperate to start drama."
Kyle responded with, "She loved the weed dealer dudes!"