Kourtney Kardashian did not expect she would date longtime friend Travis Barker: source

Kourtney Kardashian marked Valentine's Day by going Instagram official with boyfriend Travis Barker.

The reality TV star is very happy with Barker, said an insider. 

"Kourtney is very happy with Travis. She wanted to confirm their relationship, because it's something positive," the source revealed to PEOPLE.

They added, "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."

Earlier, a tipster said the couple had been "dating for about a month or two," adding that "they've been friends for a long time, but it's turned romantic."

"Travis has liked her for a while," an insider shared earlier. "He's liked her for a long time and she just got more open to the idea. He's a good guy and a really great dad. Her family and friends all really like him. Their kids all get along too, which is sweet."