Jessica and Ashlee Simpson’s Simultaneous Musical Comebacks Have Created an ‘Awkward Situation’

Sisters Jessica and Ashlee Simpson have long had a competitive relationship — but their rivalry is turning nasty as both plan their musical comebacks at the same time, a source exclusively tells Life & Style .

Pop punk singer Ashlee, 39, followed millionaire fashion mogul Jessica, 44, back into the studio — after both sisters took a 16-year break from recording!

“Jessica loves Ashlee, but it rubs her the wrong way that her own sister is planning her comeback at the same time and will likely take some shine off her return,” a pal dishes.

“Ashlee knows Jessica has been working on a new album , and it got Ashlee to thinking maybe she should try to gain a foothold in the music business again as well.”

It’s been a long time since the siblings topped the charts.

Jessica hit the big time first, selling 3 million copies of 2003’s In This Skin . But just a year later, Ashlee matched that feat with her debut album, Autobiography .

But the high-flying beauties fell to earth by 2008. Jessica’s album Do You Know sold just 173,000 copies that year, while Ashlee’s Bittersweet World moved only 120,000 — and neither has made a solo album of new music since!

But both found domestic bliss with their second husbands — Jessica with former pro football player Eric Johnson , father of her three children, and Ashlee with Diana Ross ’ actor son, Evan Ross , dad of her two kids .

However, ambitious Ashlee has kept a toe in musical waters by singing with her hubby on their self-named — but short-lived — E! reality TV show. And on July 20, she also returned to the stage for the first time in more than a decade to do a Hollywood club gig.

While Jessica took to social media to rave about the performance, another source says her younger sister’s success has sparked a crisis of confidence!

“Jess’ worst fears are that she is going to fall flat on her face and Ashlee is going to soar. Both of them launching comebacks at the same time has made for an awkward situation,” the insider reveals.

“Really, it is a big ‘if’ whether either of them is going to find success again after so many years away from music. But for sure, Jessica and Ashlee having simultaneous comebacks is going to muddy the waters — though they might want to make peace and do a Simpsons tour together!”