Styles, 22, and Jenner, 20, were dating in 2014 and they a vacation in Anguilla in December 2015. After it, they were never seen together again until this April - when they were spotted shopping in Los Angeles.

A source told People that Jenner considered Harry as "that guy" for her. But Styles has problem with his rock star mentality and attitude that made things harder for their relationship to work.

"She would love to be in a real relationship with him, but he's always had issues settling down in the past with her because he has that rock star mentality," according to the source.

However, Styles and the "Keeping Up with the Kardashians" star look forward to reboot their romance. Last week, the couple was spotted having dinner at Ysabel, according to Us Weekly.

But that does not confirm that they are in a relationship again.

"They're not fully back on, but they did hang out and had a quasi-dinner date. She was, of course, super happy, bubbly and excited that he got back in touch with her," the source added.

Two days later, they were spotted again at Malibu's Nobu.

Jenner's half-sister Khloe Kardashian in January confirmed her sister and Styles were dating. But months later, Styles was rumored to date Taylor Swift while Jenner was in relationship with rapper A$AP Rocky.

According to E! News, both Jenner and Styles have long storied friendship, so there will always possibility for them to be couple in the future.