He hadn't realized exactly how much significance had been held by that second's hesitation—the heartbeat before his brother's surprise had thawed, and arms had wrapped around his chest, the flesh one trembling.
It had been years since he'd had skin of his own to feel with, after all, and Alphonse was lost in the novelty of simply experiencing it, too caught up for several days to take in more than the fact that his brother was warm again, and his hair was soft, and Edward never, for all his exasperated looks, said anything to discourage him from touching it.
It was only after the sheer sensation had abated—only when he felt on solid enough ground to focus on the subtleties of life once more—that the habit began to catch his attention.
Because always, there was that fraction of a moment before contact, when his brother would hang back, something unreadable in eyes that usually spelled out every emotion plainly for the world to see.
Until the night that his big brother padded into his room, bare feet making mismatched sounds against the wood of the floor, Alphonse had feared it something terrible.
But then the smaller boy was climbing gratefully into bed to share the offered space, automail chill against new skin as Edward settled in close, and Alphonse was touching his hair again, running fingers marvelingly through the downy warmth of it.
His brother held back for just that single heartbeat before nuzzling in against him, bringing them close enough so that their arms were round each others' waists, the older boy's forehead resting gently against the hollow of Alphonse's throat.
They were silent for a time—before, very softly, he felt the press of Edward's lips against his collar bone.
"Sometimes," his brother whispered quietly, voice heavy with guilt. "I thought about this."
Alphonse's arms tightened carefully in response, drew the boy with scars and missing pieces and metal limbs as near as he was able. "Brother," he said, voice quietly determined. "I thought about it all the time."
Leaning down, he placed a kiss amidst the soft gold of Edward's hair.