Dean gladly went to take the bottle from her, and sank down onto the bed. God he was tired. Not tired in the sense that he needed sleep, but mostly tired in the fact that he had seen his brother go through this one time too many. He tried to keep Sam safe and every time that he failed wore more and more on him.
"Yeah..." he said, his tone skeptical and almost childlike. "I hope so." He turned the bottle up and downed a healthy portion of it before handing it back to Jo. He studied her for a moment. This couldn't be easy on her either, and she had been the one to deal with Sam the last time he was possessed here before Dean's arrival. It wasn't fair that she had to keep dealing with this too, and the last thing he wanted was for her to end up hurt the way she had been last time.
"You know, Jo, you don't have to stay. If you need to go back to your place and get some rest..." He trailed off, not sure of how to finish the sentence and certain that he didn't want to. He was giving her an out, because he knew it had to be dangerous here with him with his brother from another world out for blood, and he knew he wasn't the best company right now. He didn't need someone watching over him, keeping him company like some sort of damned funeral mourner hanging around after the service to comfort the family. He could take care of himself...but he didn't want her to go. Dean told himself that he was doing the right thing, and hated himself for doing it.