"Duck Dynasty" star Sadie Robertson has been playing coy with regards to her new relationship with Texas A&M quarterback Trevor Knight, but the two have constantly teased fans on their blooming romance by posting photos of themselves together on their Instagram accounts.

This time, Robertson has finally come out and confirmed their relationship. "We've been dating for three weeks, so it's super chill," Robertson tells Entertainment Tonight.

The "Live Original" teenager says they started off as friends, and they bonded because of their common humanitarian spirit. "He had messaged me because he goes to Haiti every year on a mission trip and he saw that I go to Haiti," she explains. "We just kinda connected through that, very much friends at first."

They became closer after they went to a Justin Bieber concert together, but Robertson says it was not a planned date. She was supposed to go with her best friend Brighton Thompson, who is also the fiancee of her cousin Reed Robertson. But because Thompson was not around, she asked Knight out.

"Trevor lives in Texas and he was messaging me, and I was like, 'Uh, do you want to go to a Justin Bieber concert with me? Because I don't have anybody to go with.' And he was like, 'Sure.' So, he came and I guess we just hit it off," Robertson recalls.

"We didn't date then. Actually, I didn't talk to him for a month after that. I was like, 'No,'" she continues. "Then a month later he called me and I was like, 'So, why didn't you just talk to me for a month?' And we ended up becoming friends and, of course, started dating three weeks ago."

Robertson is happy that her mother Korie, as well as the rest of the "Duck Dynasty" clan, gave their seal of approval to Knight.

"My family's a little scary and a little intimidating—they're big LSU fans and he plays for Texas A&M—so that was kinda funny, but he's a good guy," she says. "Even Pepaw Phil was nice!"

It can be intimidating to date Robertson because of her popularity, but the teenager says her new beau is taking everything in stride.

"Trevor has to deal with his own kinda fame—that was weird for me," Sadie says. "We're both kinda in the spotlight, but he does such a good job with it. He is a very strong Christian and he tells everybody about his faith, so we had a lot in common in that area."