Rob was noticeably absent from the star-studded party Kristen attended on April 13

“One was he didn’t want to make it the Kristen and Rob show and take away from the actual event,” our source says. “And they also have a clause in their Twilight contracts that they can only appear together at a Twilight themed red carpet together. Twilight kind of owns some of their appearances they do together until Breaking Dawn is 100% completed.”
It was weird to see Kristen Stewart, 22, hit the red carpet solo for the world premiere of Paul McCartney‘s new music video, “My Valentine,” and we couldn’t help but wonder why her boyfriend Rob was MIA.
It’s too bad work is keeping the couple from going out together, but we totally understand! And it’s great that they respect Paul McCartney enough to keep from stealing his glory at the huge premiere.

Robert Pattinson, 25, skipped the party for two reasons, an insider tells HollywoodLife.com — and neither of them hint at trouble in their relationship. Phew!