A source tells NOW magazine, "He and Kristen were arguing and Rob found comfort in Katy. She's fun to be with, not moody like Kristen. They are friends and it’s only that!”A source tells Closer magazine, "Katy has fancied Rob for years and thinks he could be The One. Maybe that's blinded her, but there''s no way he''s over Kristen yet. Her friends are telling her to wait before rushing into anything - if he''s still interested in a month''s time, then it could work. A lot of Rob''s friends think he could end up back with Kristen and say he''ll fall to pieces if she gets together with someone. They''ve been on and off so many times that no one thinks it's anything more than temporary this time."