NOTE: My blog posts are not made to be offensive in any way to people. Sorry if I spell something wrong. I am taking suggestions on what to write about...
Bella and Jacob are best friends and everyone agrees on that. Even if you are Team Edward, I don't think you can deny it. When Jacob is hurting, Bella is hurting. I think part of the reason is because Bella is part of Renesmee (before Renesmee is born). If you notice, Claire (Quil's imprintee) gets mad when Jacob raises his voice at Quil. Renesmee is also is grateful that Seth Clearwater saved Jacob in Breaking Dawn from Bella (when she attacked Jacob for imprinting and nicknaming Renesmee). So I assume that is the reason. But another reason would be because they are best friends. Don't you feel terrible when your friends are sad? I admit that there was a bit of love from Bella. But most of it was Renesmee.
Jacob had a crush on Bella starting in Twilight. It increased in New Moon. And in Eclipse it reached the maximum. When Bella picked Edward, he was crushed. When he overheard that Bella was going to marry Edward, he felt like his heart broke. I think this is because of Renesmee and also because of plain rejection. In Breaking Dawn, he felt a pull toward Bella that he didn't understand. He thought it was because he wasn't over Bella but it was actually because Renesmee was developing and it was more intense. Jacob had feelings for Bella but nothing to be compared to his feelings for Bella.
This is what I think about Bella and Jacob's relationship. If you disagree, please do not put a nasty comment. We are all entitled to our opinion.