She’s feeling “irresistible.“

Jessica Simpson ended her marriage to Eric Johnson after her 100-pound weight loss made her feel younger and more confident.

A family source exclusively told Page Six that the singer’s new body has “unleashed a whole new side of her personality.”

“She suddenly felt 21 again — except when she was 21 for real, she was a married TV star who had to behave,” the insider added, referring to her ex-husband, Nick Lachey, and their early 2000s reality TV show, “Newlyweds.”

The source also told us how Simpson, 44, had “started to want to sow her wild oats in a way she never could” because she used to turn to unhealthy habits in order to maintain a slender figure.

“In the past she always had to kill herself in the gym and via starvation diets to get slim and stay that way,” the source recalled, referencing the artist’s constant struggles with her weight.

In her 2020 memoir, “Open Book,” Simpson revealed she has gained and lost 100 pounds three different times in her life.

She also recalled her body image issues started when she just 17 after music producer Tommy Mottola told her she needed to lose 15 pounds.

At the time, the 5-foot-3 songstress weighed 118 pounds and turned to diet pills to get to a staggeringly low 103 pounds. For the next 20 years, she continued to take diet pills.

However, in 2021, Simspon focused on losing weight the healthy way. She even slammed speculation that she was using Ozempic to slim down, telling Bustle last year, “Oh Lord. I mean, it is not — it’s willpower.”

Despite Simpson’s newfound confidence, the insider further told us that her divorce from Johnson wasn’t all her doing.

“To be fair to Jess, Eric has accordingly checked out — he’s been so over it and her for a while now and so infidelity on his part is not out of the question,” the source said.

“But it’s also not out of the question on her part either.”

Johnson also seems to think that the singer is experiencing issues controlling her life, despite her being sober since 2017.

And just like Johnson, the source said that Simpson’s family and friends feared she was “in a bad place.” However, they insisted that she has not fallen off the wagon.

Simpson and Johnson, 45, first sparked split rumors last year after fans noticed they had not posted with each other on social media since 2023.

It wasn’t until earlier this week that Simpson confirmed she and the former NFL player had ended things after 10 years of marriage.

“Eric and I have been living separately navigating a painful situation in our marriage,” Simpson told People in a statement Jan. 13.

“Our children come first, and we are focusing on what is best for them,” she continued. “We are grateful for all of the love and support that has been coming our way, and appreciate privacy right now as we work through this as a family.”

Amid her heartbreak, a source told Page Six the split has inspired Simpson to release new music for the first time in 15 years.

“Jessica has been working on new music for a while, but with everything going on now, she feels it’s the perfect time to go full force with it,” a source previously told Page Six.

“She’s always journaling, and a few entries have evolved into songs about heartbreak and resilience. It’s been a very creative, albeit heartbreaking, time for her.”

Reps for Simpson and Johnson have been reached for comment.