The reality star doesn't indicate where the photo was taken, nor does she say when, but she does give some insight into the time frame.
"#FBF with the baby daddy before he was a baby daddy," she captioned the snap of the youthful pair, not knowing at the time that three children would be in their future.
Kourtney and Scott famously dated for nine years before splitting last summer after he was photographed getting a little too frisky with an ex-girlfriend. Late last year he went to rehab and has reportedly been sober ever since (He's even abstained from booze during several trips to Las Vegas).
The former couple, though, are very amicable with one another, as evidenced by Kourtney's social media post.
On Jan. 25, Kourtney even gave a status report on their relationship.
"We're not together," she told Ellen DeGeneres. "I feel like every day is different, but we're totally getting along. Like, we have three beautiful kids together."
She added: "He's family. He'll always be."
On a recent episode of "Kocktails With Khloe," Scott also addressed the somewhat negative perception the public has about him.
"A lot of people think I only care about money and cars and don't realize it's more just about insecurities and how much I care about my friends and my family," he said. "I'd really rather never be in a tabloid again, but if I'm going to be, at least it be about, 'This guy isn't who everyone thinks he is.' "
His family is what's important to him.
"People say, 'Focus on work. focus on work. Make more money.' I have money. The more money I have, the less happy I am," he said. "The only thing I'm trying to focus on is calming down and focusing on the kids and trying to be a good dad."