Jennifer Aniston’s Steamy Trysts With Matt LeBlanc Behind Brad Pitt’s Back

In one of Hollywood’s best kept secrets, JENNIFER ANISTON cheated on husband BRAD PITT with her “Friends” co-star MATT LEBLANC, Matt’s father has claimed to The National ENQUIRER in an explosive world exclusive interview.

According to Paul LeBlanc, his son – who played lovable rogue Joey Tribbiani on the classic sitcom – boasted that he and Jennifer enjoyed passionate make-out sessions in their dressing rooms!

Speaking to The ENQUIRER at his Florida home, 73-year-old Paul also claimed his son – who has an estimated $65 million net worth – blew a small fortune on booze and women!

What’s more, Paul claimed his son blasted his “Friends” co-star Matthew Perry – famous for his role as Joey’s roommate and best friend Chandler Bing – as an “a–hole,” and often wanted to punch him!

“I’m obviously proud of what my son has achieved, but he’s not the ‘Joey’ everybody loves,” Paul claimed to The ENQUIRER. “Matthew is a control freak, and the more money he has the more f—ing ruthless he is.”

As for his son’s 10-year run on “Friends,” Paul said: “He had fun, that’s for sure. It was the making of him and the entire crew.”

That crew included Matt, Matthew, David Schwimmer, Courteney Cox, Lisa Kudrow and Jennifer, who wed big-screen hunk Brad in 2000.

Jennifer and Brad were Hollywood’s hottest A-list couple before divorcing in 2005 after Brad famously fell for now-wife Angelina Jolie on the set of “Mr. & Mrs. Smith.”

But, according to Paul, his son and Jennifer were more than “Friends” while filming the classic sitcom.

“Matthew got on very good with Jennifer Aniston,” Paul told The ENQUIRER. “They would make out in the dressing rooms. He told me about it. It was when she was married to Brad Pitt!”

While his son was this-close to Jennifer, “he always said David Schwimmer was kind of dry, a bit too serious, and he always liked Lisa Kudrow,” Paul revealed to The ENQUIRER.

While a rep for Jennifer said the actress “has never been romantically or sexually involved with Matt LeBlanc,” and Matt’s lawyers slammed the claims as false, Paul also ripped the lid off his son’s private life, including his boozing and fondness for women.

Matt, 47, was married to model Melissa McKnight, now 50, from 2003 to 2006. They have a daughter, 11-year-old Marina. They split after Matt admitted to groping a stripper at a Canadian nightclub.

There were also rumors the actor was involved with his co-star, Andrea Anders, on the short-lived NBC sitcom “Joey.”

Paul claimed to The ENQUIRER: “When he was accused of cheating, Melissa shut the sex off. It didn’t last much longer after that. He pays $15,000 child support every month.”

Matt now plays a fictionalized version of himself on the Showtime comedy series “Episodes,” but his father predicted that Matt’s lifestyle will short-circuit his career.

“Matthew has always been wild and reckless,” Paul said. “He was as good-looking as anyone in Hollywood, but he isn’t going to age well. He’ll be a fat, little guy because he pigs out.”

Three years ago, Paul was living in a six-bedroom home on his son’s eight-acre ranch in Colorado.

But after a bizarre spat over a $15,000 motorbike, Matt evicted him, and they haven’t spoken since.

“It was horrible,” Paul – who now lives in a $45,000 condo in Clearwater – claimed to The ENQUIRER.

“I went to the house with a friend and a locksmith was changing the locks and the county sheriff was there. I wasn’t allowed back in, and I lost thousands of dollars worth of possessions.”

Despite their rift, Paul said he’d forgive his son.

“I would welcome him back, but I could never forget what he’s done to me,” he said. “I lay in bed going over it all in my head every night.

“I’ve written him letters and sent him religious books. But I don’t know if he’s ever read them or just throws them in the trash.

“But I’m just going to get on with my life. I don’t want anything from Matthew, and if I don’t ever see or talk to him again, then fine.”