If there's one thing a weekend with Jennifer Aniston will do to a guy, it'll leave him with feelings of inadequacy ... about his hair. So it's understandable that John Mayer would feel the need to do a little mane maintenance after spending a cuddly, paparazzi-captured few days with the enviably golden-tressed actress in Miami.

On Wednesday, the Casanova crooner, 30, was snapped exiting a New York salon, where a stylist unfortunately snipped his locks into a look last seen on Ralph Macchio when he was waxing on and waxing off at the behest of Mr. Miyagi.

But was his mini-makeover a way to take his mind off his high-profile new squeeze, 39, who is still in Florida filming "Marley & Me" with Owen Wilson?

"They already miss each other," a Mayer mole pines to People, whose latest cover trumpets, "Jen & John's Hot New Romance!"

Adds another indiscreet insider, "It's very real. They've been seeing each other for a few weeks now."

The latest issue of In Touch ("Jen's Hot New Love!") features photos of the two soaking up harmful UV rays as they lounge side-by-side on a chaise, with one pic appearing to show the ridiculously tattoo-sleeved singer resting his noggin on the bikini-clad A-lister's tanned, toned shoulder (see them snuggling here).

John supposedly spent the weekend holed up in Jen's $3,000-a-night presidential suite at the luxe Mandarin Oriental hotel, although the robustly coiffed couple repeatedly emerged for food runs.

They reportedly refueled everywhere from the see-and-be-seen Casa Tua eatery to the more downscale aisles of a Publix supermarket.

As for how they met, the tabloids have a few different theories. Us Weekly ("Jen & John Suddenly in Love!") maintains the wooing began over e-mail several months ago; Life & Style ("Jen's Dating John Mayer!") posits that they were introduced by business acquaintances; and In Touch and Star ("Jen & John Hook Up in Miami") follow the National Enquirer's lead in claiming mutual pal Sheryl Crow played matchmaker.

Meanwhile, there are concerns the former pity party-tossing Mrs. Brad Pitt could get her heart stomped on by the romantically fickle troubadour, whose exes include buxom actress Jennifer Love Hewitt and stacked starlet Jessica Simpson.

"Girls fall for him hard because he's charming," a snitch tattles to OK! ("Inside Jen & John's Risky Romance"), "but he has a reputation for crushing the girls he's with."

Predicts a source to Us, "He's a real ladies' man. It won't last."

Mayer kept his usually rapidly moving piehole closed when shadowing shutterbugs quizzed him about Aniston, although he did offer this scintillating sound bite to In Touch about his Miami getaway: "My weekend was good."

Also good: his behavior as he made the club scene in New York this week.

"He just hung out with his friends," a spy tells the New York Post, "and wasn't flirting with any girls."

John Mayer fixes his feathered 'do as he scours New York for acid-washed jeans, a Members Only jacket and a Journey album.

As for his new 'do, he took to his blog to explain what inspired him, helpfully posting vintage photos of Michael J. Fox, Shaun Cassidy, Mary Lou Retton and Kristy McNichol, whose shaggy mop, as he put it, is "the goal personified."

"Today I set off on my newest project: to grow and maintain an authentic '80s style feathered haircut," Mayer cheekily penned. "It's something I've wanted to do for some time and I'm very excited to bring this amazing look into today's pop culture landscape."

And the feathered cut does so much more than merely make you look like you're wandering around the mall while contemplating buying a ticket to the 3 p.m. showing of "Weird Science."

According to the singer, it "projects an attitude of ease and quiet confidence that seems to have all but eluded our generation. This is a work in progress, and as my hair grows longer it will serve to become a more stirring and poignant statement."

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