Stewart 22, cheated on Pattinson after she was caught having an affair with director Rupert Sanders. After a much hyped breakup Pattinson decided to give the actress another chance because he really loves her.
"He really loves her and is scared (of) what others might do to him in a relationship," hollywoodlife.com quoted a source as saying.
"He thinks that they might use him or have different intentions. He is comfortable with Kristen, and he is happy with her, and she knows it. He feels that she is the best for him," the source added.
The couple met on the sets of movie 'Twilight' and have been together ever since.