The 29-year-old model shared a photo to her Instagram that showed her and Gronkowski lounging on a boat in Miami.
“Me and big foot,” she captioned the image along with a yellow heart emoji.
Kostek went on to share her periwinkle and baby blue “boat day” outfit in her Instagram Story, complete with a two-piece swimsuit, crop top and joggers, which she modeled while leaning over the yacht’s shaded bench.
“Baby blue bikini details coming soon,” Kostek teased in a following story where she reposted her image with Gronkowski, 31.
The last glimpse she shared with her 953,000-plus followers was a three-part collage that showed her and Gronkowski were catching rays, sipping drinks and exchanging romantic kisses on what appears to be the bow of the yacht.
Kostek and Gronkowski reportedly met during a charity event in 2013 began dating two years later.
When the gameshow got around to Kostek’s 2019 Sports Illustrated Swimsuit cover, the model and “Wipeout” host said the achievement was a “euphoric moment.”
“At that point in my life, it all hit me at once. I truly blacked out,” Kostek told Kyle Brandt on Wednesday. “I was sober, but I blacked out. It was a high on life.”
Meanwhile, Gronkowski expressed his support for Kostek’s magazine debut.
“It was incredible,” the Tampa Bay Buccaneers player said. “I think I found out right after my birthday. So it was like a double birthday.”