Dierks Bentley Celebrates 18th Anniversary with Wife Cassidy: 'Love This Girl'

Dierks Bentley certainly still feels that fire with his wife Cassidy.

On Thursday, the “Burning Man” singer, 48, shared a sweet message to his wife, 48, on Instagram in honor of the couple’s 18th anniversary.

Bentley posted a carousel of photos featuring images of his wife. The first snap is a portrait of Cassidy in the crowd at a concert, while the second features Bentley with his arms wrapped around Cassidy's waist on a mountain top. Another photo features the couple posing in front of a colosseum, the next showcases Cassidy in an angelic-like costume presumably during Halloween and another is a solo shot of Cassidy in black glasses laughing in front of a stunning mountain landscape. Bentley concluded the post with a video of his wife dancing with a Dalmatian. 

“Happy Anniversary to us! Love this girl. Couldn’t imagine life without you babe. Random pics…way too much life to sort through on my phone!! But what a life! ❤️” he captioned the images.

Bentley and his wife met in middle school but spent years in and out of each other's lives before tying the knot in Mexico in 2005.

"We met in eighth grade, back in Arizona. It's a pretty crazy story of just going back and forth with the right time or the wrong time, or right place, wrong time, all that stuff," Dierks told The Boot. "Finally, I was playing a show in Las Vegas, and opening for George Strait, and she walked on the bus. I kind of knew that that was the moment."

In 2007, Bentley told PEOPLE: "I had a crush on her the whole time, but I wasn't cool enough. I was way too immature and into drinking beer and guns and blowing things up." Cassidy agreed, adding, "He was just trouble."

Bentley explained that the couple tried dating in high school and beyond before they married. When the “Free and Easy” performer moved to Nashville at age 19 and Cassidy was working at an advertising firm in San Francisco, they were in a long-distance relationship.

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"I used to write her all these crazy love letters that I'd FedExed out to her," he told PEOPLE. "That's why I married her! I was worried I'd get blackmailed with those letters!"

His wife added: "I did save them and thought I could always sell them on eBay!"

Bentley and Cassidy are parents to three children: daughters Evalyn Day and Jordan Catherine, born in 2008 and 2010, respectively, and son Knox, born in 2013.