Plenty of players have taken off their shirts mid-game at this year's US Open, but only one on-court costume change was deemed offensive enough to issue a code violation.
It wasn't Rafael Nadal, who last week apparently struggled to find a tank top that fit between games.
It wasn't Novak Djokovic, whose towel failed to cover his manspreaded legs while his torso was also exposed during a relaxed costume change during the second round match.
And it certainly wasn't the Djoker's effort today, which saw cameras trained on the Serbian champ's bare chest as he luxuriated in his shirtless masculinity with the knowledge that he was both about to win a quarter-final match, and could get away with lazing on the court half naked.
No. The only on-court costume change that officials found worthy of disciplinary action came six days ago when French player Alize Cornet returned to the court after a 10-minute break, noticed her fresh shirt was back-to-front, and discreetly scurried to the back of the court to whip it off for a few seconds and dared to expose her crop top.
Actually, it's unconfirmed whether Cornet was actually shirtless for any time at all. Cameras failed to capture a moment in which her upper garment was fully lifted making it entirely possible that just spun the neck hole around and never actually removed it.
We're nitpicking here, but these details are important. The most important detail is the most obvious one — that Cornet is a woman, and the other offenders aren't.
When you take that all into account, there's no getting around the double standard that's been on display.
Today, cameras loved a bloke sitting back showing off his sweaty bare chest and belly, and no one in the audience complained. When a woman did a quick T-shirt shuffle facing the back corner of the court, all hell broke loose.
Yes, we went through this last week. The double standards were pointed out. The umpire was lashed with sexism complaints, and US Open chiefs were forced to clarify the rules and admit Cornet hadn't broken any.
That the umpire didn't realise Cornet wasn't doing anything wrong is telling. It indicates that a woman changing her shirt on the court — which is allowed — is unusual. When it happened, no one knew what to do, but players like Djokovic have been doing it unquestioned their entire careers.
The image of Djokovic captured at today's quarterfinals not only reminded us of the double standard, but proved the hypocrisy that was on display when Cornet was warned. The fact that not an eyebrow was raised today tells us exactly why nothing should have been made of the incident during Cornet's match either.
It also shows that tennis has a woman problem.
The US Open was the first grand slam to offer woman equal prizemoney to men back in 1973, but 45 years later it's clear the tournament still has a way to go when it comes to equality.