The two well-known celebrities each share Olympic-sized careers, so the odds of the pair creating a lasting relationship seemed in their favor. However, the couples ride together has been cut short because of several factors, including distance.
"Both the mileage between their homes and their heavy career demands interfered with their ability to maintain the relationship," a rep tell PEOPLE.
While Brinkley has been busy launching her new line of bubbles, or Prosecco's Bellissima, Mellencamp was touring in the spring with plans of a tour this summer.
However, even though they're going through a break-up, they must be on good terms since they have each "vowed to remain best of friends."
Brinkley described her relationship with her then current boyfriend in June admitting that he didn't seem like a promising companion when they first met in the Hamptons back in 2015.
"I thought, 'Oh my gosh, we're really opposites. He's kind of a throwback from another time, like a silent cowboy,' " adding, "But then we talked and realized that we do have a lot of shared interests."
In fact, they both shared a bond between their kids. Their similarity in age may have also contributed to their companionship, Brinkley being 62 and Mellencamp 64. Brinkley appreciates a man who dates women closer to their age.
"I know guys that go out with girls that are so, so young. They'll throw some reference out, and they're like, 'What's that?' " Brinkley said.
"When it comes to relationships, there is something nice about just being the same age."
Brinkley and Mellencamp seemed to take their relationship at their own pace, deterring any questions about whether or not they would get married.
"You never really know what's going to happen," she told PEOPLE. "John and I are two people that have very full lives. We're just trying to enjoy each other when we can see each other and try not to put too much [pressure] on it."