They've been plagued by split rumours as reports emerged that they'd had a series of blazing rows.
The beautiful pair, who recently relocated to LA in a bid to boost their careers, were alleged to be 'on a break', but are in fact still as loved up as ever.
Rosie's rep Liz Matthews told OMG!: ''Rosie and Jason are very happy together and she just spent the weekend with him on the set of his new film.
''There are always rumours of a split but the truth is they have never been happier.''
And the issue of age was said to be one of the main issues that Rosie and Jason have been struggling with, but the 19-year age gap hasn't seemed to have affected them.
A source told MailOnline that, despite rumours of a possible engagement, the couple have been plagued by constant arguments.
''There is no other person involved. They love each other very much and are not making an announcement because they're still hoping to work things out.''
They added: ''But things have not been good, there have been lots of arguments and they both need some space.''
Rosie, who previously dated Tyrone Wood, left London last week for a girls' holiday in Ibiza, posting snaps of herself cuddling up to her girlfriends, and is said to have jetted back to see Jason at the weekend.
The source continued: ''They are taking some time out from each other. Bear in mind there's an almost 20-year age gap between them - they are going to run into some issues.''
The pair first went public with their relationship back in April 2010 when they were spotted looking loved up at Coachella.