Simone Biles' boyfriend isn't intimidated by Zac Efron.

Arthur Nory Mariano, a Brazilian gymnast, had an interesting response after Efron planted a kiss on his girlfriend, who has been killing it for the United States' gymnastics team in the Rio Summer Olympic Games.

Efron surprised the superstar gymnast in Rio and, according to her tweet, planted a kiss on her:

Though she had massive success in Rio de Janeiro, Biles being all smiles wasn't solely about all the medals and hardware she's set to take home to the United States with her.

For his part, Efron seemed to enjoy the company of the famed "Phenomenal Five:"

Apparently Mariano has seen enough as he fired off a photo alongside his girlfriend on Instagram and gave a pretty clear message to Efron, likely joking around:

A photo posted by Arthur Nory (@arthurnory) on Aug 17, 2016 at 11:47am PDT

Biles, 19, has had a great run at the Rio Games, taking home four gold medals and one bronze.

The young gymnast earned gold in the women's vault, women's team all-around, women's floor exercise -- which is a specialty of hers -- and women's individual all-around. She also took home the bronze in the women's beam.

While he hasn't had quite the same success as his girlfriend, Mariano, 22, earned a bronze medal in the men's floor exercise at the Rio Games.

Perhaps that will be enough to hold off Efron.

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