"Can you say it again?" Sam's fingers curl around Dean's wrists, and Dean is holding on too because lately that's all he does.

"Which part, Sam?"

"About being your brother," Sam whispers. "He never... got that quite right."

"You're my brother, Sammy." The lump in his throat surprises him. Because really, this? This simple thing is what slips past his defenses? He reaches a hand around the base of Sam's neck and squeezes the knot of muscle there, drawing his brother's head closer to his.

Something seems to give inside Sam. "Oh, god, Dean."