Meet the New Jen Aniston!

It seems like the whole world has been waiting for Jennifer Aniston to find love again. Now, in a blossoming romance with singer John Mayer, the actress,39, seems happy and giddier than ever before, telling friends that she is head over heels for her younger man.

But Jen's learned a few things from her previous relationships, including the seven years she spent with ex-hubby Brad Pitt, and this time she's not only taking it slow, but making sure she calls all the shots!

While John,30, was performing at the opening of MGM Grand at Foxwoods casino in Conneticut on May 17, Jen was filming scenes for her movie Marley & Me in Philadelphia. Friends of the actress say never again will Jen drop everything for the man she dates. It's important to her that she keep her newfound sense of independence.

"This is a whole new Jen," a pal of the actress tells OK!. "She's trying new things, taking a risk, and is game for getting out of her shell, living her life and trying to be happy."

A friend of John's agrees, telling OK, "She doesn't rush off and go on vacation with John, and she's made it clear she will not be a groupie at his shows."

Apparently, her hard-to-get attitude is working on the heartthrob crooner. "He was smitten with Jen and came to visit her on set," John's pal says. "They're actually working around her schedule more than anything!"

The friend adds, "Jessica Simpson texted John all the time, but Jen waits a few days to text him back. She hasn't stopped her life for him. She's fun and flirty, but hasn't outright said, 'I want you,' which is something John isn't used to."

For more on Jen's new dating strategy, pick up the new OK! — on sale everywhere Thursday!