The New And Improved Shania Twain!

Shania Twain

SHANIA TWAIN has turned her big farewell tour into a big kiss-off to her ex-husband!

Seven years after catching him cheating with her best friend, Shania’s doing everything she can to upstage her hated rival, sources told The National ENQUIRER.

“Shania’s got a body to die for now,” said a family friend. “She’s ready to show it off so her ex can see what he threw away!”

The 49-year-old singer has gone blonde for the “Rock This Country” tour, and longtime fans are shocked by Shania’s sexy makeover.

The Canadian-born songstress was happily married to Robert “Mutt” Lange – who produced four of her hit albums – for 14 years.

That was before she caught the cad having an affair with her BFF, Marie-Anne Thiebaud!

According to insiders, the lingering hurt inspired Shania to work out “like a demon” to get ready for this year’s concerts. “She’s still a little obsessed by what happened,” the insider told The ENQUIRER.

As The ENQUIRER reported at the time, Shania divorced Mutt in 2008 – and, in a bizarre romantic twist, fell in love with Marie-Anne’s jilted husband!

“When that happened,” Shania revealed, “I thought, ‘Forget it, this is more than I can handle – I’m never going to sing again.’ ”

She married Marie-Anne’s ex, Swiss-born Nestlé exec Frédéric Thiébaud, in 2011. Shania has kept civil relations with Mutt for the sake of their 13-year-old son, Eja – but the same can’t be said about her former friend!

“I don’t see her – ever,” Shania said about Marie-Anne.

Shania – whose 1997 album, “Come On Over,” remains the best-selling country record of all time – is eager to gush over Marie-Anne’s ex-hubby, though.

“Fred wears a lot of hats,” she told a reporter. “So being together a lot, it’s a very multidimensional life.”

Shania confessed that before meeting Fred she “felt very insecure and inadequate.”

Calling him “my partner,” she added: “[We] live our lives in tandem. We’re together a lot.”

“It’s bizarre how things worked out with Shania and Mutt,” the source told The ENQUIRER. “But that’s why there’s country songs!”