Robert Pattinson tells Kristen Stewart: Prove you didn't sleep with Rupert Sanders
But Now can reveal that the pair's reunion has been far from easy.
Although sources tell us repentant K-Stew, 22, wants to get a ring on her finger by next year, Rob's still desperate to make sure she's told him the whole truth about her affair with married director Rupert Sanders.
And we hear R-Pattz, 26, has even told her: 'Take a lie-detector test to prove you didn't sleep with him.'
His demand comes as the pair appeared in public for the first time since their tentative reunion a month ago.
But while they've been putting on a united front, they have a long way to go before Rob, 26, can really forgive.
Read the full story about Robert Pattinson and Kristen Stewart and see our exclusive pics of the couple leaving an LA eatery in Now magazine dated 29 October 2012 - out now!