The model couldn't help but flash a smile when her hunky beau got cheesy in front of the cameras.
While Gronk looked dapper in his checkered light-blue suit, it was his model gal pal that stole the show in a fitted white midi-dress that featured a corset-inspired bodice.
In a second photo from the red carpet, the couple opted for a more serious pose.
The 27-year-old Kostek recently opened up to Fox News about her romance with the athlete, 29.
“I am such a private person,” she told us last year. “It was hard at first when people would send articles with my name on it. It’s an overwhelming feeling to read something that you have no control over.
"But like most things, you get strong when you have to deal with situations like that. It’s gotten a little easier. And usually, the people that are close to you know the truth. So it’s one of those things where you just have to let people think what they wanted to think.”
Kostek also clarified, “We first got in touch once I resigned from the team. I always knew who he was before I was even a cheerleader. I knew who he was on the roster. I just never paid any mind. Once I resigned is when we finally met.”
Kostek told Fox News she’s always envisioned herself as a Sports Illustrated Swimsuit model and believes the popular magazine offers an empowering message for women.