Brad Pitt is worried that one of wife Jennifer Aniston’s studly co-stars will make a move on her.

His blood pressure skyrocketed over 34-year-old Jen’s steamy onscreen love scene with Jim Carrey in the box office blockbuster “Bruce Almighty” — and at 39, Brad’s worried that Jen’s leading men will only get younger and more handsome.

“It was one thing when Jen was just a TV star on ‘Friends,'” said an insider.

“Brad knew Jen considered those guys — Matt Perry, Matt LeBlanc and David Schwimmer — as brothers. She’d never hook up with them.

“But now Brad is watching Jen pair off with one sexy hunk after another in her films.”

In a wild love scene in “Bruce Almighty,” Carrey’s character hurls a scantily clad Jen, who plays his girlfriend, on the bed for a passionate sex romp.

Carrey is just the latest in a long string of big-screen heartthrobs for Jen.

In last year’s hit “The Good Girl,” Jen played an unfaithful wife who carries on a torrid affair with her younger co-worker, played by Jake Gyllenhaal.

In 2001’s “Rock Star,” Jen lip-locked hard-bodied Mark Wahlberg, a former pop star and underwear model known for his red-hot sex appeal.

And she just wrapped up a romantic comedy with Ben Stiller, playing the secret mistress of Stiller’s married man.

Even worse, Hollywood’s newest stud muffin Ashton Kutcher has admitted that he’s had the hots for Jen for years.

“I was obsessed with her,” Kutcher — the 25-year-old star of “That ’70s Show” and MTV’s “Punk’d” — said in an interview.

“That photo of her with her legs crossed from Rolling Stone was the screen saver on my computer through college.”

He also said he bet a pal $1,000 that he’d take Jen out on a date — and even braced Brad about it!

“Ashton approached Brad at a party and asked for permission to take his wife out,” a friend of the couple revealed.

“Brad wasn’t even mildly amused.

“He’s well aware that his wife is fast becoming Hollywood’s latest movie It-girl.

“He also knows that her leading men are going to get younger and better looking with each movie.”