WHILE we won’t be waiting around for a formal “thank you,” sources say that Jessica Simpson’s mom, Tina, is GRATEFUL to The ENQUIRER for exposing her ex-hubby Joe’s secret gay lifestyle – because it saved the family’s billion-dollar business!

The couple’s divorce was final­ized on April 22, seven months after Tina filed her petition in a Texas court. But despite ear­ly threats from Joe that he was going to “play down and dirty” and target Jessica’s uber-success­ful fashion empire, which Tina co-owns, in the end, the 34-year marriage went out with a whimper instead of a bang.

“Tina would never publicly ad­mit how happy she was about Joe’s gay lifestyle being exposed, but quietly she is thrilled with The ENQUIRER’s reporting because Joe wound up folding like a cheap suit,” said a family friend.

IN NOVEMBER, THE ENQUIRER broke the bombshell story that Joe, 55 – a former Baptist minister who manages the careers of Jessica and her sister Ashlee – paid $600 for a steamy session with 32-year-old male escort Joey Anderson at New York’s Mandarin Oriental hotel.

“When that story hit the stands, the you-know-what hit the fan,” the friend noted. “Joe was com­pletely humiliated, and the en­tire Simpson family went into a tailspin.”

In March, we reported that Joe – who has denied being gay – was seeking a $250 million payout from 53-year-old Tina, claiming he was entitled to an even split of her half of Jessica’s billion-dollar busi­ness. Friends feared the 32-year-old blonde bombshell would have to sell the company to help her mom fund the staggering divorce settlement.

But “Tina reminded Joe about what The ENQUIRER had pub­lished and said that if she had to, she would use that among other things in court against him,” the friend continued.

THAT was enough to soften Joe’s stance, and the couple ulti­mately agreed to a fair division of assets. He’s keeping a mansion in Sherman Oaks, Calif., along with his two Mercedes and other personal property. She gets the onetime family home in Waco, Texas, as well as her Range Rover and Porsche.

They’ll also split profits from Joe’s management of their daugh­ters’ careers and Tina’s partnership with Jessica.

“Joe was ready for a fight, but Tina stood her ground and made sure he understood that he’s the one who cheated on her with a male escort,” added the friend.

“Needless to say, Joe didn’t want to relive the sordid details about his gay sex life in open court.”