Robert Pattinson and Kristen Stewart are still single. The couple who broke up last year has neither reunited and nor started dating other celebs in the Hollywood fraternity or non-showbiz personality. Fans wonder what could be reason that the young actor and actress are still single and not ready to mingle. Lets take a look at some of the possible reasons.

Robert Pattinson is still in love with Kristen Stewart: Pattinson and Stewart had a 4-year long relationship, and reportedly, the couple was too much in love with each other before their relationship was plagued by cheating rumors. There have been various media reports, which revealed that Pattinson is still not over his break-up from Stewart.

"Kristen that he taught he knew is still stuck in his head. This is why it is so hard for him to move on, he can't trust girls anymore," source close to Pattinson revealed, reported Longlive Gossip.

Stewart only wants Pattinson: When Stewart was caught cheating on Pattinson with "Snow White And Huntsmen" director Rupert Sanders, she went ahead and apologised to the "Twilight" actor in public. Reportedly, Stewart still wants to be Pattinson and her only wish in life is to reunite with the "Twilight" star. A source revealed that the "Still Alice" actress wants to reunite with Pattinson on her 24ht birthday.

"Kristen wants to celebrate her upcoming birthday with her close friends in LA, and she wants Rob to join them as well," reported Hollywoodlife.

Pattinson's rumored relationships with other women have not lasted long: It is not like Pattinson has not tried going on dates with other females. A few months back, Pattinson was in news for dating Sean Penn's daughterh Dylan Penn. However, the purported romance fizzled out in no time as Pattinson reportedly wanted to go back to Kristen.

"Rob swore to Dylan that he was over Kristen and would never go back, but she's like an addiction. He agreed to see her a few weeks ago and was hooked again, " a source revealed to OK! Magazine on Nov 19, 2013.

Stewart and Pattinson are focusing on their film careers: After staying in limelight for their relationship, the couple has now shifted their focus to their professions. Both of them are choosing meaty roles to make a mark in Hollywood.

Pattinson will be soon seen in some of the most endearing Indie films, whereas Stewart is prepping up for her coming-of-age role in "Still Alice."