Ashlee Simpson Ross Reveals Secret to 10-Year Marriage to Husband Evan: 'The Key to It All...' (Exclusive)

Ashlee Simpson Ross has one simple secret to her 10-year marriage to Evan Ross — love.

While catching up with PEOPLE at DSW's back-to-school kick-off at Lombardi House in Los Angeles on Friday, Aug. 9, Ashlee, 39, opened up about what has made her marriage with Evan, 35, last.

"I mean, we love each other," she says. "I think the secret is that we have grown together. And I think that if you can grow together and watch as we all change or evolve and stick together, that's probably the key to it all."

Since tying the knot in August 2014, Ashlee and Evan have become parents to daughter Jagger, 9, and son Ziggy, 3. The singer is also a mom to son Bronx, 15, with ex-husband Pete Wentz.

In honor of their 10-year wedding anniversary, the family matriarch tells PEOPLE that she and Evan have been discussing "renewing our vows or doing something special."

While nothing has been decided yet, one thing is certain: The couple will not be returning to reality television anytime soon.

"There is no more reality TV in my future," says Ashlee when asked if she and Evan are open to doing another show after the 2018 E! reality series Ashlee + Evan. "And it's so funny because I get asked about it. I'm like, no, I'm done. I really enjoy my private time."

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Evan echoed similar sentiments about their marriage in June, telling PEOPLE that he believes it has lasted as long as it has because they "love each other, and it's meant to be."

"And we enjoy each other's company, and we love our children," he added.

He, Ashlee, Jagger, and Ziggy are the faces behind DSW's back-to-school campaign, which Sarah Crockett, senior vice president and chief marketing officer of DSW, told Footwear News was a natural fit.

“Each family member has their own distinct personal style, exemplifying the diverse footwear styles offered at DSW. Back-to-school at DSW is all about looking great and feeling confident for the full family — whether that be for the kids getting ready for the school year or parents looking for a style refresh for themselves," said Crockett.

Ashlee tells PEOPLE that she's also "a huge fan of DSW."

"And I think it's a great place for the family to go, and especially in these moments like back to school, where everyone is excited to get their new shoe and, what's my vibe this year going to be? So, I think that it's such a great place with such great variety," she says.

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"So, I'm so happy to have this partnership," continues Ashlee. "And I'm a sneaker girl, so it's brilliant."