The One Direction singer, 22, and Fernandez-Versini, 32, first met when he auditioned for The X Factor in 2008 at the age of 14 (he wasn't successful but wound up back on the show as a contestant two years later).
The source close to Payne tells Us Weekly that the pair are dating — it's "not serious ... but they're enjoying things."
According to the source, the couple “hates that it’s out there,” but Payne is “kind of relieved at the same time because now they don’t have to be paranoid about getting caught.”
Payne separated from longtime girlfriend Sophia Smith in October 2015, while Fernandez-Versini is in the middle of a divorce from Jean-Bernard Fernandez-Versini, who she secretly married in July 2014.
“[Liam] wanted to be back in a relationship for a while,” the source added. “[He] never liked the whole random hookup thing.”
The pair attended the Brit Awards separately on Wednesday, February 24. Payne and Louis Tomlinson accepted the best video award for “Drag Me Down” on behalf of One Direction.
Want stories like these delivered straight to your inbox? Sign up now for the Us Weekly newsletter!