Harry Styles, Caroline Flack Back Together? 1Der Celebrates 19th Birthday with Ex-Girlfriend, 'Wants Nothing to Do with' Taylor Swift [PHOTOS]

Reports confirm that recently-single One Direction heartthrob Harry Styles celebrated his 19th birthday on Thursday evening with none-other-than ex-girlfriend Caroline Flack. Now that Taylor Swift is totally out of the picture (with rumors swirling that neither star "wants anything to do with each other" ever again), Styles appears to be enjoying the single life. A bunch of pals partied with the 1D crooner at the popular London nightclub Groucho to ring in his b-day... and 33-year-old Flack was one of the revelers among the crowd. So that goes to beg the question... will (the much younger) Styles get back together with the U.K. television starlet?

Styles turned 19 on Friday (Feb. 1), so he decided to kick off the celebrations early. The birthday boy hit up London's La Bodega Negra restaurant with good pals DJ Nick Grimshaw and actor James Corden before heading off to the club to join a bunch of other show bizz friends... including "Xtra Factor" star Flack. And upon exiting the club, it appears Flack had a successful club night out:

Rumors have it that since their split after a short-lived romance in 2011, Styles and Flack have remained very close friends... so it remains unconfirmed if the duo are actually "dating" again. Flack was most likely just enjoying a fun night out on the town in honor of a good pal's b-day. And it looks like the crew indeed had a wild good time... Styles didn't arrive back home until 3 a.m., tweeting:

@Harry_Styles: "I feel olllllllllllldddddddddddd."

Styles' fellow One Direction band mates apparently didn't take part in the late-night festivities.

Styles' three-month fling with Flack back in 2011 caused some controversy, considering he was ony 17 at the time (and Flack was 32). Still, the British starlet defended the couple's relationship, once telling Now magazine:

"I keep thinking, 'What have I done wrong?' But I haven't done anything wrong. What's hard for me to get my head around is people saying it's disgusting. I don't think it is... I feel like I shouldn't have to worry about what I do. But it's a social thing that people aren't accepting of big age gaps. Some people tend to see the negative immediately and that's what I find really strange. If two people like each other and get on, why does anyone else find a negative in it? I know it's human nature for everyone to gossip. But why say it's bad? No one's being hurt at all in any way."

If the duo do plan on eventually getting back together, Flack shouldn't have to worry about Swift coming back in for a rebound... reports confirm that Haylor is most likely "never ever getting back together."

So what do Mstarz fans think... is a rekindled romance between Styles and Flack currently in the works?