He didn't know so much about the blood not being a hardship, but the sex was something that Sam could easily agree upon. She seemed to appreciate it just as much as he did, otherwise she was just really, really good at faking it. "I guess I start thinking about it sometimes and it gets under my skin," Sam admitted, mind instantly going to his brother. Dean didn't like it. Sam could tell, without hearing it from his mouth, that he thought that Sam's interactions with Ruby were sick. Especially this kind.
"You already know," Sam declared, turning his head to look at her. "You know what I want." More specifically, who. It was why they were so close. Sam and Ruby had a common goal and they were both going to do whatever they had to in order to make sure that it was met, demolished, and danced all over when the task was completed. Then...well, maybe there wasn't going to be a then. Not for him. But if there was, then he'd maybe go find Dean. Grab a beer. Watch the game. Do what he did best: played the role of the irritating little brother. He missed it.