Life with Jose Mario dos Santos Mourinho Felix has never been very easy for his employers.
An early indication of the Portuguese manager's bloody-mindedness came at Benfica in 2000. After just nine games in charge, Mourinho squared off with new club president Manuel Vilarinho, who wanted to install his own man in place of the then-unknown young coach. Mourinho tested the water with a demand for a contract extension after a win over local rival Sporting, and resigned immediately when Vilarinho refused.
Not surprisingly, the Benfica president, who had been in the post for about five weeks, later admitted he might have made a bit of a mistake.
Mourinho's relationship with Chelsea owner Roman Abramovich was also a little testy. Despite bringing unprecedented success to the London club, the marriage of convenience ended in September 2007, just a few games into the new season. Still, the divorce cannot have been that acrimonious if this was Abramovich's response to Mourinho's failure to find a run-around for his kids in Italy.
Wherever he has gone, Mourinho has provided a benchmark for success and controversy. At Real Madrid, he has taken the game to new heights. Ever since his arrival, there has been a battle to fight with players, the board, the press, UEFA and his fellow professionals.
Mourinho's antics were sufficient to make even the genial, sadly departed Manolo Preciado lose his rag in 2010 (although the two later made their peace). In a country where heated words are often the result of the slightest provocation, Mourinho possess the reddest cape of them all.
But he might have picked the wrong bull to taunt this time. Real president Florentino Perez is not a man to lie down quietly if challenged. After winning re-election to lead the club in 2009 he immediately started weeding out players brought in by the previous regime of Ramon Calderon, and began to build his own Galacticos 2.0.
The former president accused the incumbent of merely being Mourinho's puppet after the Portuguese won his battle for control of the club with Jorge Valdano. Calderon also opined that Mourinho thinks only of himself and of his own image, to the detriment of all the clubs he has managed.
Perez may finally have found something he and his sparring partner can agree on.
The Real coach's theatrical flourish before the match against Atletico and his employee's later admission that the league was impossible was a turning point in their relationship that led to a veiled rebuke from Perez during the club's annual dinner.
Talk of a locker room rift has been rife for some time: the Spanish-speaking players led by Sergio Ramos and Iker Casillas on one side, and the Portuguese/Brazilian faction with Cristiano Ronaldo and Marcelo at its head.
Ramos was dropped after a bust-up with Mourinho, and the Real coach became increasingly paranoid about a mole after sensitive information found its way into the press. Perez favorites Ramos and Casillas are the primary suspects.
Mourinho's decision to drop the Real captain to the bench for Malaga's 3-2 win on Saturday was, according to the coach, based on form. In fairness, Mourinho sees more of Antonio Adan than the rest of us but it was a bold statement, and not necessarily one of purely sporting intent.
In an exchange with a Spanish journalist last week, Mourinho responded to his on-air claims (via Football.co.uk) that goalkeeping coach Silvino Louro, a confidant of the coach, was keeping more than just an eye on the form of Adan or Casillas, alluding to "three black sheep" in his flock.
If the Real coach has had enough of the constant wrangling at Madrid, and his increasingly hangdog expression suggests that he has, there is no quicker way to invite the ax onto his neck than to cross Perez. Over the past few months he has done little else.
It would be no surprise to see Mourinho leave the club if the spirit around the Bernabeu continues to be more festering than festive. Even the nicest man in the whole of Spain, Vicente del Bosque, left the club in rancorous circumstances and was quoted in Richard Fitzpatrick's book El Clasico as calling Perez "a smart-a*** dressed in a pair of braces."
Perez had sacked del Bosque a day after winning the league title because he "wasn't modern enough for Real Madrid."
Mourinho certainly is, in all the ways good and bad that being a modern manager entails. It remains to be seen whether Perez still thinks he's the man for the job.
With all that's going on at Chelsea, Abramovich may just be reaching for his used car contact list again. And Mourinho might well jump on board again.