"Bella actually falls in love with Jacob in New Moon. It's understandable why this fact didn't occur to her: Bella had fallen in love only one other time and it was a very sudden, dramatic, sweep you off your feet, change your world, magical, passionate, all consuming thing. She didn't recognize the much more subtle falling in love she experienced with Jacob. She was only aware that she preferred being with him over everyone else. That he was constantly on her mind and that his happiness was essential to her own. She also enjoyed being phyiscally close to him in a way that she didn't with her other friends. But it took her a while to add up all the pieces."

Isabella Marie Swan-Cullen and Jacob Black's relationship is complicated because Jacob, a Shape-shifter, is in love with Bella. Although she is romantically involved with Edward Cullen, a Vampire.

This relationship eventually became a deep family-like bond between Bella and Jacob. After the latter imprinted on her daughter, Renesmee.

Their Life and Death counterparts are Beau Swan and Julie Black.

In the moves, Bella is portrayed by Kristen Stewart and Jacob by Taylor Lautner.

Twilight

"I really liked Jacob. He was someone I could easily be friends with."

In Twilight, Bella only encounters Jacob four times after she moved back to Forks.

She first meets him on First Beach on La Push where she successfully flirts with him to gather information about the Quileute tribe's legends regarding Vampires. He tells her what he knws about the "Cold Ones" and how the story relates to the Cullen family. Though her flirt was a trick to gather information, she expresses a liking in Jacob and feels guilty for tricking him.

The second time, Jacob and Billy visit Bella's house again. While Billy and Charlie prepare to enjoy a Baseball match, Bella and Jacob hand out.

The third time, Jacob visits Bella with his father. Billy warns Bella about Edward Cullen and his family.

The fourth time, Billy sends Jacob to Forks High School on Prom night to try and persuade her to break up with Edward, quoting "We'll be watching you." Jacob crashes the Prom and dances with Bella before Edward takes over again, much to his dismay.

Jacob first appears in the movie adaptation of Twilight with his father to deliver Bella's Chevy pick-up truck and teaches her how to handle it.

New Moon

"It's just that, I know you're unhappy a lot. And maybe it doesn't help anything, but I wanted you to know that I'm always here. I won't ever let you down- I promise that you can always count on me. Wow, that does sound corny. But you know that, right? That I would never ever hurt you?

Bella and Jacob cease to meet since Prom night.

Months after Edward leaves Forks, Bella comes to find Jacob and persuades him to help her rebuild two dead motorcycle to experience adrenaline rushes in order to hear Edward's voice in her mind, but as they spend more time together, he starts to open up about his feelings for her and Bella is torn by her own feelings to both Edward and Jacob. After Jacob phases, he is prohibited by Sam Uley from seeing Bella, saying that he could hurt or kill her. When Laurent attempts to kill Bella at the Meadow, Jacob appears in Wolf form with his Pack and runs off to kill him.

Bella visits Jacob after one week of solitude. He furiously orders her away after learning from the tribe that she has known about the Cullens being Vampires. One night, Jacob visits her at her house and gives her clues to help her figure out what he has become. She eventually discovers that he is now a shape-shifter. The next morning, she visits him and they finally tell each other everything. It turns out that Victoria has come to kill Bella, given Edward killed her Mate, James. Jacob tells this to Sam and they prepare a hunting troop for Victoria. Also, Jacob was ordered not to be close to Bella because it wasn't safe for her.

As he is hunting Victoria, Jacob cannot spend much time with Bella because he's either on patrol or sleeping. This causes Bella's depression to creep back in and to keep it at bay, she jumps off a cliff to hear Edward's voice again but ends up also drowning. If not being killed by Victoria first. But Jacob pulls her out before she could seal her fate, keeping Victoria at bay with his "repulsive, wet dog smell" and herself from drowning. When Alice Cullen unexpectedly returns to Forks because she'd "seen" Bella jump, Jacob tries to take Bella to safety, but she refuses and walks away. Two days later, a sullen Jacob appears at her house and shares a brief conversation with them separately that leads them to almost kiss until they receive a call from Edward. Jacob takes the call and tells him that Charlie is planning a funeral, which leads him to believe it is Bella's. Alice has a vision of his suicidal desire and she and Bella rush off to stop him. Jacob promises to protect Charlie while she is gone, but, knowing that she will be heading to the Volturi's headquarters to find Edward, pleads her to stay. She refuses and he is deeply hurt by her decision.

At the end of the story, a lovesick Jacob is forced to stay away when Edward returns to Forks with his family and reconciles with Bella. Jacob turns in her motorcycle to Charlie to make him ground her, not knowing that she is already grounded for leaving without his permission.

Eclipse

"I'm exactly right for you, Bella. It would have been effortless for us- Comfortable, easy as breathing. I was the natural path your life would have taken... If the world was the way it was supposed to be. If there were no monsters and no magic..."

Their relationship wavers again in Eclipse. For weeks, Jacob continuously stays from a distance while Bella tries to contact him. After Emmett and Paul almost have a fight hunting Victoria, Jacob visits Bella and Edward at school to warn them. Jacob struggles to keep away from Edward but be with Bella and even tries to convince Bella to choose him instead of Edward. This leads to a big argument between them and Jacob decides to tolerate the Cullens to see Bella more often.

He forces a kiss on her, which Bella is outraged by and punched him for it, but breaks her hand instead. They soon make up however, though Jacob continues to fight for her, a bit more carefully this time. He makes her a bracelet for a Graduation present, much to her pleasure. It's a wooden, carved Wolf charm. When the Cullens discover an army of Newborn Vampires coming for Bella, Jacob volunteers to help, willing putting aside his still roaming issues for the time being. When he learns that Bella and Edward are engaged, he is enraged and pretends to sacrifice himself to make Bella willingly offer a kiss, which is the only thing keeping him from killing himself. As Bella is kissing Jacob, she visualizes a future with him and realizes that she is in love with him after all. Edward learns about this kiss while it goes on because "Jacob's thoughts are very loud."

Despite Bella realizing her feelings for Jacob, she stays by her decision, leaving him heartbroken. Once back at home again, Bella cries over having to reject Jacob, with Edward comforting her all night. Edward sends Jacob a Wedding invitation sometime after, prompting him to run into the woods and live as a Wolf to escape the pain.

Breaking Dawn

"Bella, things are different with us now. But you'll always be my best friend and I'll always love you, Bella. But I'll love you the right way now. There's finally a balance. We both have people we can't live without."

For two months, Jacob has gone missing since Eclipse. He attends the Wedding reception and asks Bella to dance with him. When she tells him about her honeymoon plans, he nearly gets into a fight with her and Edward and Seth and Sam are forced to restrain him and take him away before he phases into his Wolf form.

Edward impregnates Bella on their honeymoon and they are forced to return to Forks immediately. Jacob believes that she has already turned into a Vampire as this point and engages a solo attack against everyone's advice until he learns of Bella's pregnancy. Edward suggested that Bella have an abortion and have a baby with Jacob instead, but Bella refused. Jacob promises to kill Edward if Bella dies, which Edward gladly agrees to. When Sam plans an unprovoked attack against the Cullens to prevent Bella's child from being born, Jacob takes his place as the rightful Alpha Wolf by leaving Sam's Pack to protect her, with Leah and Seth joining him. During the pregnancy, he and Bella feel strongly drawn to each other in ways they didn't understand. When Bella goes into labor, Jacob gives Edward his permission to turn Bella into a Vampire to save her and the baby's lives.

After he daughter, Renesmee is born, Jacob believes Bella is dead and tries to kill the baby, but instead imprints on her. Jacob tells Sam about this, forcing the Packs to make permanent peace with the Cullens because harming or killing anyone a Wolf imprints on is against tribal law with no exceptions.

Bella is unconscious for two days while undergoing her Vampire transformation. After awakening, Edward takes her on her first hunt to quench her thirst before she can see Renesmee. She is firous when she learns about the imprinting and even more so when she hears that he nicknamed her daughter "Nessie" after the Loch Ness monster. Jacob tells Bella they were drawn to each other while she was pregnant because of Renesmee and insists that he only wants her to be safe and happy.

When the Cullens talk about leaving Forks again, Jacob believes it's because of Charlie, Bella's father. He visits Charlie and tells him that Bella had to "change." He also tells Charlie he doesn't live in the world he thins he does and even phases into his Wolf form. Charlie is horrified. Bella and Edward were not happy about it but were glad they were able to stay in Forks.

When they find out that the Volturi are coming to destroy their family, Bella has legal documents forged for both Jacob and Renesmee to help them escape, trusting her daughter in his care and accepting wholeheartedly his imprinting on her.

As the confrontation is about to break into a fight, Bella hands Renesmee over to Jacob and they share a tearful hug. Bella also reassures Jacob that he will always be her best friend. The situation is resolved peacefully when Alice and Jasper bring back Nahuel, another half human half Vampires Hybrid and his Aunt from South America to give the Volturi reason to leave peacefully.

By the end of Breaking Dawn, Jacob and Bella finally put their issues behind them and become best friends once again, with Bella accepting him as her future son-in-law.