During the three months that Donald Trump has been president, the New York businessman has shaken his fair share of hands — and has refused to shake few others. But perhaps at no other point in recent history have a president’s handshakes been such a point of derision. So frequently is President Trump pictured turning an innocuous gesture of camaraderie into a grand display of machismo and oneupmanship that his handshakes have become notorious.

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The handshake drama came to a head this week at a NATO summit Thursday, during which Trump was pictured locking a number of politicians in bizarre grips and violently shaking not only their hands, but their entire arm by jerking them in close to him. A handshake face off with France’s new president Emmanuel Macron featured prominently this week.

Time spoke Friday with India Ford, a London-based body language expert and the founder of Talkbodylanguage, who described the incident with Macron as Trump “showing Macron who's boss.”

“It's another aggressive move by Trump; he's pulling Macron towards his own face and he's basically saying ‘you will come to me, whether you like it or not,’” she told Time. “You can see Macron trying to get away from the situation — he puts his arms on Trump to stop him pulling him inwards. This handshake makes sense when you see the previous video. Trump's done this because of what Macron’s just done. It's as though he's saying, ‘Do you know who I am? You will not be doing that again.’”

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Speaking with Mic Thursday, body language expert and retired FBI counterintelligence and counterterrorism operative Joe Navarro said that President Trump may not understand the intended meaning of a handshake.

“Diplomacy is about getting along,” Navarro said. “One of the things we do with our handshakes is we establish comfort. We're saying, ‘I'm your friend. I'm the person you're going to be working with.’ That's what the handshake is supposed to be for, not some sort of sophomoric challenge between two alpha males.”

Beyond the strange handshakes, President Trump was also roundly mocked for a similar behavior after he was seen shoving the prime minister of Montenegro, Dusko Markovic, out of his way. Author JK Rowling later shared the clip on Twitter, writing, “You tiny, tiny, tiny little man.”

Ahead of the aforementioned handshakes and shoving, President Trump made headlines earlier this week after two incidents involving first lady Melania — referred to by some as handgazi and swatgate, respectively — seemed to show that she has a strong aversion to holding his hand.

All in all, it’s been an odd week in hand news.