The couple – whose relationship PEOPLE confirmed on Saturday – have been dating since late 2015, according to The Sun.
Over the weekend, Payne, 22, changed his Instagram profile picture ... to one of him and Fernandez-Versini, 32, snuggled together for the camera, Payne seemingly shirtless.
Source: Liam Payne / Instagram; FameFlynet
— Liam (@Real_Liam_Payne) February 26, 2016
And on Tuesday, Payne shared a solo shot of his new love for International Women's Day, captioning it, "Happy #internationalwomensday to my favourite woman in the world hope I make you as happy as u make me X"
The One Direction-er and Fernandez-Versini met in 2010, when he appeared on X Factor as a competitor along with his future bandmates; and the two stayed in touch after she signed with 1D's management company.
GVK / Bauer-Griffin / GC Images; Brian Rasic / WireImage
The relationship has "been going on for a while," the source said. "Both are very similar and happy."