Why did Joe reject Betty if he was going to walk out on Norma anyway?
I don't get it.
Betty has revealed her true love for Joe, and we know Joe cares for her, but he rejects her and says the deal he has with Norma is just too good to pass up. He tells Betty to leave and to go back to her fiancee.
As soon as she leaves, however, he tells Norma he's hitting the road and tries to leave her and everything she's given him behind, at which point she shoots him.
So why exactly did he reject Betty? Was it to do his friend who was engaged to her a solid? What is because he thought that ultimately he couldn't make her happy?