She wanted the blood. He could see the desperation so clearly in her eyes. Just like me, Sam thought greedily, hands gripping at her hips, it's just like me.
"If you want it, it's yours," Sam told her, eyes falling shut again as her lips teased at his neck. It was seductive, yet so very threatening at the same time. Sam knew that Ruby could lose control at any second. She could snap into those primal urges that all vampires carried within them and kill him, right there on the spot. But she wouldn't. Sam knew that she wouldn't. As long as they kept her blood consumption under control and as long as Ruby held on to what she was, she would never kill him.
But that didn't necessarily meant that Sam would protest her hurting him. He squeezed at her hips, unknowingly releasing a gasp as soon as she nipped at his flesh. She didn't break skin, no, but the thrill of her playing with his throat like that, combined with the feel of her soft skin against his weakest of spots made Sam feel such a rush that Sam didn't even realize that he had pulled his head back to rest against the gravestone, giving Ruby perfect access to his neck, until it was already done. "Go ahead," he urged her, tilting his head to the side just enough so that he could meet her gaze, "I owe you. After everything I took from you, I want to give it back. Please, take it." Yes, begging. Begging was good. It would make Ruby feel like she was in control. Like she was doing him a favor.
And, in a very important way, she was. She was letting him study her. She was giving him the closest damn thing he could get to his old addiction as possible and she was doing it far more willingly than Sam could have ever dreamed of. "Please," he said again, turning his head more, that way Ruby could see every inch of his neck perfectly. She would drink. She would get stronger. That tired demeanor she had taken on earlier would vanish and she'd be full of life - his life - and they both would get what they wanted. They would both walk away from this with something, wouldn't they? So long as Ruby remembered to avoid killing him in the process, that was.