I don't know what to tell you - I really like having a girlfriend.
Jonathan loves Bella. He loves spending Valentine's Day together. He loves introducing her to his family, and loves talking about her with his friends. A small rift at a birthday party isn't enough to break their bond. Jonathan is happy.
But what about Bella? In its second half, the film revisits the same events through Bella's eyes in reverse chronology, casting every previous moment with her in a new, revealing light.