There's a spot on the back of Neville's neck, just under his hairline, that Draco turns into when they sleep, and nuzzles.

During the war, when Draco'd first changed sides, first come to them with names and dates and a body shaking from Cruciatus, Neville protected him from the others, bodily protected him, and Draco, tired and afraid and too Slytherin to give a shit about appearing brave, had dipped his face and pressed right there, just closed his eyes and hidden.

Harry had asked him how he could trust Malfoy, of all people, "who spent seven years torturing you?"

"That wasn't *torture*," Neville said.

After that, they left Draco alone.

Snape had made a potion for him, to ease the tremors, and once his hand was steady enough to make it himself, he spent hours with Neville, learning how to grow the ingredients in the middle of August. In the heat of the greenhouse, Neville wrapped solid fingers around Draco's slender hands, and helped him plant and pot and coax life from dusty seeds and under-watered soil.

In his spare time, to get away from the everpresent eyes of comrades who never attacked him but never quite trusted him either, he went back to the greenhouse and harvested, chopped and diced and husked and modified the potion to relieve other symptoms as well.

He was good at potions, always. Not as brilliant as Snape, perhaps, but diligent, and single-minded. He knew what he wanted, and Draco was accustomed to getting what he asked for.

When his mother and father first blinked and looked at the world with whole minds, Neville sank to his knees, shuddering, and Draco sank with him and wrapped his arms around him and buried his nose in the back of Neville's neck.

"This is my spot," he told Neville once.

Neville smiled, and brushed his hair from his eyes. "It's all your spot," he said.