You and Jasper have been dating for a while. You're both vampires after all.

Jasper has a problem controlling his bloodlust. He doesn't do good around humans. When Edward brought Bella, a human. To the house. You knew something was gonna go wrong. Everyone was gonna be there, Carlisle, Esme, Emmett, Alice, and Rosalie

It was Bella's birthday and she was opening gifts when suddenly she got a paper cut. Smelling the blood, Jasper starts trying to get to her

Edward: "No!"

Edward shields Bella from Jasper