Kourtney Kardashian didn't expect her friendship with Travis Barker to turn romantic.

Kourtney Kardashian

Kourtney Kardashian

The 41-year-old TV star recently went public with her burgeoning romance, but according to a source close to the brunette beauty, the relationship has actually taken her by surprise.

The insider said: "She was single for a while and didn't expect that their relationship would turn romantic.

"She feels very fortunate. She loves spending time with Travis."

Kourtney and Travis, 45, recently made their relationship Instagram official.

And the 'Keeping Up with the Kardashians' star - who has Mason, 11, Penelope, eight, and Reign, six, with Scott Disick - is glad that their romance is now out in the open.

The source told People: "Kourtney is very happy with Travis. She wanted to confirm their relationship, because it's something positive."

Kourtney's family are said to be “supportive” of her new romance.

However, the TV star and Travis - who has Alabama, 15, and Landon, 17, with his ex-wife Shanna Moakler - are taking things slowly for the time being.

An insider recently said: "Kourtney and Travis have been spending a lot of time together, but they’re taking their time and trying not to move too fast. No one is surprised by their relationship.

"They have big modern families [and they] both are dedicated to their kids. They come from these modern families with modern relationships. Both of their families are supportive. It’s still very new, but they are both very excited by how easy it all has been."

The new couple made their romance Instagram official earlier this week when Kourtney uploaded a picture of her hand intertwined with Travis’.

Although she didn't post a caption on the snap, Travis commented with a black heart emoji.