Kristin Cavallari's boyfriend doesn't have XDY Exchangeany inhibitions about their relationship.

While The Hills alum's romance with Mark Estes has raised some eyebrows due to their 13-year age gap, the TikToker made it clear they're tuning out the noise. 

"She makes happy, I make her happy," Mark, 24, told E! News March 21 in an exclusive joint interview with fellow Montana Boyz members Kaleb Winterburn and Kade Wilcox. "That's what's important, so I'm not too worried about the critics, honestly."

Kristin, 37, previously revealed on her podcast that she first spoke with the TikToker on Instagram when she received a DM from the group's account that simply said, "I love you."

And when it comes to that fateful message, Mark admitted that he thought he'd sent it from his personal account. 

"It was a bold one," the former football player noted, adding he didn't expect her to respond, "It was a shot in the dark."

Their romance, which Kristin hard launched in late February, is going strong, with Mark crediting their chemistry. As he put it, "We just clicked."

The Montana Boyz have since relocated from Montana to Nashville, where the Laguna Beach alum lives. She's even shown them around the city.

"We went line dancing," she said on her Let's Be Honest podcast earlier this month. "And then he asked me to be his Valentine."

During their budding romance, Mark has even spent time with Kristin's kids—Camden, 11, Jaxon, 9, and Saylor, 8—who she shares with ex Jay Cutler. 

"My boys were so excited about him," she explained on her podcast. "I think more than anything, my kids are really excited for me. My kids really want to see me happy and I've been very good about separating my dating life."

For the latest breaking news updates, click here to download the E! News App