MIAMI &#8212 Questions of fashion in men’s underwear used to boil down to a simple line: boxers or briefs?

These days, you could add a few more: animal print or camouflage? Jock strap or thong?

Just take a look at papi, a Miami Lakes-based underwear maker that showed off flashy colors, camo prints and bright yellow and red – gasp – thongs during Miami’s recent fashion week.

As men have taken a bigger interest in their appearance, even the humble boxer has not been immune to innovation. For that you can thank Calvin Klein, the designer given credit for introducing the first designer underwear brand – still going strong on its 25th anniversary.

“Underwear is a $600 million business for Calvin Klein, and it’s a double-digit growth,” said Patricia Edwards, retail analyst for Wentworth, Hauser and Violich. The brand is even focusing on rolling out underwear-only stores.

But with Fruit of the Loom and Jockey remaining the top sellers, are men ready for truly creative looks down under?

“We are really looking for the young confident guy who feels good about himself, who doesn’t want to wear what everybody else wears,” said Alan Zelcer, President and C.O.O of Isaco International, which owns the line.

And many men have taken an attitude toward undergarments that might have sounded unmanly a few decades ago.

“I do wear fashionable undies and fashionable socks all the time,” said 27-year-old David Crespo, of Hialeah. “It’s about your attitude for the day.”

On the other hand.

“Humbleness for guys in their underwear choices is not a bad thing,” said Matt Graham, a 23-year-old accountant from of Winter Park, Col., who prefers regular boxers.

Carl Younis, a 28-year-old IT consultant from Fairfax, Va., said he was pretty sure bikini briefs were still “a huge no-no among just about everybody our age.”

And muscular models weren’t enough to persuade many of them that comfort wasn’t the first concern.

“As long as the underwear didn’t sacrifice comfort for fashion, I’d consider wearing them,” said Derek Halpern, 22, a blogger from Mineola, N.Y. “Overall, I’ve never considered wearing fashionable underwear, but maybe that’s what I’ve been doing wrong in my life.”