The muzzles flew off this week, with the stars flinging such pointed barbs at each other you'd swear they were in the midst of divorce proceedings. Or at an AA meeting where someone had slipped Jagermeister into their orange juice.
But, no.
Because while dismissing Madonna as looking ''like a f---ing fairground stripper'' during her latest tour, Elton John was sitting comfortably with Molly Meldrum for an interview that aired on the show Sunday Night.
''She's such a nightmare,'' John said. ''Her career is over, I can tell you that. Her tour has been a disaster and it couldn't' happen to a bigger c---.''
Meanwhile, Justin Bieber seemed totally oblivious to the fact that he might be causing offence when he bagged out Prince William for losing his hair to British Rollacoaster Magazine.
''I mean, there are things to prevent that nowadays, like Propecia,'' said the 18-year-old pop star.
''I don't know why he doesn't just get those things, those products … Have you not got it over here?''
But if Bieber's comments were the result of stupidity - he un-ironically boasted in the same interview that he was ''growing up'' - then what can one say of Brazilian novelist Paulo Coelho slagging off James Joyce's Ulysses?
One of the most influential books of all time, Ulysses was dismissed by Coelho as ''a twit'' in online journal Folha de S.Paulo (by which Coelho meant the book is all style, no substance). And herein lies our collective disappointment. ''A twit''?
Can't Coelho, the author of The Alchemist and the recipient of France's Legion d'honneur, do better than to use the sort of insult you'd toss your nine-year-old brother's way after he gives you a wet willy?
Still, at least he had the smarts to pick on someone who died 71 years ago, and therefore can't retaliate.
Because those who are alive don't always respond so well, such as when American author Gore Vidal compared writer Norman Mailer with serial killer Charles Manson.
How did Mailer respond?
He headbutted him in a green room, where they were both waiting to go on an American TV talk show.
Perhaps Elton John and Justin Bieber would do well to take heed of a message that Call Me Maybe pop star Carly Rae Jepson sent to Bieber earlier this year in an MTV interview, when she heard about his habit of playing jokes on friends: ''Watch your back.''