The tennis stars of today may be hot, they may be passionate, but where are the outbursts of John McEnroe at his most “You cannot be serious” intemperate?

And, yowza, the shorts. Where are the shorts?

Many, including Serena Williams, Andy Roddick, and David Nalbandian, have had on-court meltdowns—but for the new superbrat crown, arise Nick Kyrgios.

At the Montreal Masters, while changing ends with his Swiss opponent Stan Wawrinka, Kyrgios told Wawrinka that the player he is romantically linked to, 19-year-old Croatian women’s player Donna Vekić, had had sex with Kyrgios’s fellow Australian player Thanasi Kokkinakis.

Or as Kyrgios hissed: “Kokkinakis banged your girlfriend, sorry to tell you that, mate.”

For that, on Thursday, the ATP (Association of Tennis Professionals, which oversees the men’s tour) fined Kyrgios $10,000.

The ATP called Kyrgios’s eye-wateringly horrible remark “insulting.” The 20-year-old player may also receive additional penalties, it said.

There is no word on the truth of what he said, by the way, or even if Wawrinka and Vekić are in a relationship themselves. Yes, all round, clenched eugh.

Wawrinka retired from the match, apparently injured.

Immediately after saying it, Kyrgios didn’t seem that apologetic.

He told a reporter, completely incoherently: “I thought he was getting a bit lippy at me, so I don’t know…it was in the moment sort of stuff. I don’t really know, I just said it.”

To another group of reporters, he said:

“We were having bit of an exchange. It was obviously the heat of the match…I thought we both competed well…it just sort of came out…I thought I stuck to my game plan well. Obviously it happened, I’m not going to deny it.”

Kyrgios said there had been tension on court. “There was a bit of looking and come-ons, that’s sport…both of us competing,” he mumbled.

Had the men talked about what happened afterward? “No.”

That’s not what Wawrinka, 30, said. In his post-match interview, in which he spoke a thousand times more fluently, he said (later translated): “My reaction is that it’s not the first time that he has big problems on the court in terms of what he says, and in terms [sic] how he acts.

“I just hope that the ATP will take big measures against him because he’s young, maybe—but there’s no excuse. Every match, he has problems. Every match, he behaves very badly.

“On top of that, the problem is that he doesn’t just behave badly towards himself, he behaves very badly towards the people around: the other players, the ball kids, the umpires. I really hope the ATP will take major action against him this time.”

In the locker room, the men had confronted each other, Wawrinka said: “He tried to avoid me, but I confronted him.”

What had they said to each other? “It will stay in the locker room,” said Wawrinka. “But I think there are things, regardless of how you are, regardless of the stress you have on court, there are things that you just can’t say. And regardless of whether or not he sidesteps it, I think the way he behaves on the court, he has big problems.”

Wawrinka wrote about his feelings on the matter just as passionately on Twitter, denouncing Kyrgios’s behavior in the strongest terms.

By Thursday night, Kyrgios was apologetic. He wrote on his Facebook page: “I would like to take this opportunity to apologise for the comments I made during the match last night vs Stan Wawrinka.

“My comments were made in the heat of the moment and were unacceptable on many levels. In addition to the private apology I’ve made, I would like to make a public apology as well. I take full responsibility for my actions and regret what happened.” On Friday, his reps released another apology from Kyrgios: “I apologize to Donna Vekić and her family, as well as Thanasi Kokkinakis and his family for dragging them into something that wasn’t deserved for them.”

It was all so different a year ago, when Kyrgios burst into the tennis firmament as the first Wimbledon debutant ever to reach the quarterfinals of the tournament.

In the 2014 competition he knocked out then-world No. 1 Rafael Nadal, many said with the shot of the tournament, struck as a deliciously eccentric winner from between his legs.

The lead-up to last night’s controversy was played out at this year’s Wimbledon. In the third round, playing Milos Raonic, Kyrgios smashed his racquet, which bounced into the crowd.

He went on to win the match, but then, in the fourth round, playing Richard Gasquet, he fell out with the umpire (something of a specialty, he is often rowing or taking issue with them) about taking off a pair of socks and holding up play.

And then, while losing against Gasquet, Kyrgios appeared to give up entirely—not bothering to attempt to return Gasquet’s serve; in tennis, this is known as “tanking.”

Afterward, having lost, the sulky brat said he hadn’t “tanked” when he very visibly had.

“I kept playing. It’s just frustration. It’s tough out there. I don’t know what else to say. I’m not perfect out there. You have ups and downs.”

Did he not hear the booing, as he behaved in the way he did, one journalist asked.

“Yeah. Then I started playing well and they started cheering.”

Gasquet’s serve was just too good to return, Kyrgios claimed, implausibly.

“Of course I tried…I did move,” he protested.

Another journalist asked how he felt to be “the new bad boy of tennis.”

“Not at all, to be honest. Just ’cos I show emotion I’m bad…so…whatever.”

Perhaps the most telling interview Kyrgios gave was to Australian journalist Patrick Stack before Wimbledon began this year.

He felt emboldened to have beaten both Nadal and Roger Federer in different tournaments, he said. A “great team” was helping him.

John McEnroe had said Kyrgios’s was a name to watch out for, Stack said. Kyrgios said it was “inspiring to know a guy like that, a legend of the game, has so much belief in me.”

Kyrgios said he felt no pressure, that he thought he could have fun at this year’s tournament, that he had proven himself, but confirmed a previous quote that he did not “love” tennis.

“I don’t love the sport at all. I was pushed majorly into tennis when I was 14. I like the sport to an extent, but don’t think my passion is completely in this sport. I think basketball is the sport I completely love. Past players that haven’t loved the sport have done great things.”

The reporter may seem incredulous, but the most refreshing thing about Kyrgios, depressing as it may sound to sports-world idealizers, is how he sees what he does.

“The reality of it, it is more of a job,” he said, with the stuff of contracts to deal with. “I still enjoy myself when out on court,” Kyrgios added.

As his nasty encounter with Wawrinka shows, though, the “fun” he’s having seems far from that.

His words to Wawrinka make Kyrgios, who has just taken on Lleyton Hewitt as his coach and mentor, seem immature and unpleasant. He’s young, of course, and McEnroe certainly consolidated his fame—and made money—on his infamy.

But infamy and rudeness without attention to excelling in one’s game—and a huge change in attitude—might make for ever diminishing returns, and a short career, for Kyrgios.

Tennis fans like drama queens only up to a point. McEnroe became an engaging commentator, and witty, urbane elder statesman for the game.

Even when he was “you cannot be serious-ing,” there was a watchable kind of crazy to McEnroe. Kyrgios right now just seems a bit nasty, undisciplined, and immature.

Kyrgios’s mother has said he “wasn’t in a good head space” following a recent Davis Cup match he lost.

Hewitt, brave man, has his work cut out, as Kyrgios prepares for what is expected to be his next major appearance at this year’s U.S. Open, starting August 31—where, if Kyrgios chooses to provoke them into doing so, the crowds will be all too ready to boo him.