Entertainment

ARMS AND THE MAN

DOES Mario Lopez suffer from biceps envy?

This Disease of the Vain usually strikes hunky guys who come into close contact with even hunkier guys. They see a set of biceps larger then theirs, and they go bananas.

Lopez, who just took over the role of Zach, the exacting director of “A Chorus Line,” is mighty proud of his biceps. So proud, in fact, that he refused to wear Zach’s costume, a tan sweater with long sleeves.

It’s an iconic outfit, based on that worn in real life by “A Chorus Line” creator Michael Bennett, and it’s been worn by countless Zachs in productions of “A Chorus Line” all over the world for the past 30 years.

But “Flex” Lopez wanted to wear a brown shirt with short sleeves so that he could show off his biceps. (The audience, I gather, isn’t complaining.)

The only trouble is, Flex is sharing the stage with a pair of biceps larger than his. They belong to Nick Adams, who plays Larry, the assistant choreographer.

Larry’s iconic costume is a navy blue tank top with the number 17 on it. For “A Chorus Line” nerds, that number is significant – there are 17 performers auditioning for the eight spots in the chorus.

Flex, sources say, was concerned that Adams’ biceps would upstage his, so he requested that Adams wear a hoodie over his tank top, which Adams does whenever he’s next to Flex.

For the opening dance number, Adams does wear just the tank top – but he’s been banished to the back of the line, so you really can’t see him or his biceps.

Flex, meanwhile, is out there front and center, dancing and flexing up a storm.

This may seem like small potatoes, and I wouldn’t argue that it’s not.

But consider this: The people who put this revival together believe “A Chorus Line” is a masterpiece that needs very little tinkering.

The staging, the scenery and, yes, the costumes, are near replicas of the original 1975 production.

But the fact is, after a second year on Broadway, shows often depend on TV stars like Flex to fill the house. And so if he wants to wear a short-sleeve shirt, he can wear a short-sleeve shirt.

Officials with “A Chorus Line” insist that director Bob Avian made the decision to throw a hoodie over Adams.

“When they stood side by side, you couldn’t tell them apart,” one person says. “They looked too similar” – like two Chelsea boys on their way to the gym.

As for the battle of the biceps, I’ll leave it to you to decide who’s got the better set.

Check out the photos running with this column, and e-mail me your preference.

I’ll run the results next week.

See you at Equinox!

michael.riedel@nypost.com