Biting your own medal is one thing. A Japanese mayor learned you don’t bite someone else’s.

Olympic athletes have long been photographed biting their medals, a celebratory if not entirely hygienic gesture.

But typically they’re biting their own medals. A mayor in Japan learned the hard way that chomping on someone else’s doesn’t go over as well.

Mayor Takashi Kawamura of Nagoya apologized after biting the gold medal of Miu Goto, a member of the Japanese national softball team, during a ceremony on Wednesday as he stood in front of a backdrop promoting coronavirus safety precautions. He was immediately pilloried on social media, where some Olympians said they would be furious if it happened to them. Others just thought it was gross.

Toyota expressed its displeasure in a statement, saying Mr. Kawamura “did not pay respect and honor to the athlete, nor had consideration to prevention of infection.” (Goto also plays for the company’s corporate team.)

Mr. Kawamura said he later recognized it was “extremely inappropriate conduct.”

“I apologize from the bottom of my heart for making her and others feel uncomfortable and causing troubles to them,” he said.

Local news reports said Mr. Kawamura had visited Toyota to deliver a letter of apology, but he waited in the car while his aides went inside. The city of Nagoya received about 4,000 complaints from citizens criticizing his act, according to reports.

Naohisa Takato, a judo gold medalist, wrote on Twitter that he handled his medal with care so as not to damage it.

“Ms. Goto is so generous that she did not get angry,” he wrote. “If I were her, I would cry.”

Nao Kodaira, a speedskater who won gold at the 2018 Winter Games in Pyeongchang, South Korea, tweeted that he would have cried and “wouldn’t be able to recover for a while.”