Robert Pattinson and Kristen Stewart have reportedly called it quits again.

The on/off couple - who initially broke up last year after Kristen's affair with married director Rupert Sanders, before reconciling in autumn - are said to have ended their four year relationship a second time round, People magazine reports.

Despite sources insisting it seems to be a temporary split for the on-screen 'Twilight' couple, Kristen, 23, has already turned to her close friends for support.

A source said: ''Kristen is super sad. She's leaning on her friends.''

It is thought the British heartthrob had struggled to come to terms with Kristen's ''momentary indiscretion'' and things didn't return to how they use to be, despite her desperately trying to regain his trust.

A source previously said: ''Rob is at a point where he sometimes ignores her. He'll go out and won't respond to her calls or texts right away. Things will be strained for a while.

''She knows she has to go along with it. She is working hard at the relationship.''

Things seemed to become too much for the couple on the 'Bel Ami' actor's 27th birthday last week (13.05.13), where he reportedly avoided a surprise party planned by his other half to spend time with his male friends instead.