"He never got over you," Sam told her, not accusative. If anything, he was trying to reassure her. That was weird, since he was sure Dad hadn't been celibate. Not that he'd ever let him see anything. Dean might have.

"I was the same after Jess... it was like I couldn't think of anything else. An itch between my shoulder blades, fire in my gut. I didn't have time for anything or anyone until we killed Azazel."

It was sort of sad that he finally understood Dad and then he went and died.