"Al," the Fullmetal Alchemist whimpered, face flushed an interesting shade of scarlet. "I'm sorry, already."
And the boy's brother paused just long enough to favor him with a singularly disapproving look.
"Oh, no you don't," Alphonse informed him dourly. "That's what you said last time. And the time before that. And," he added, dragging the feather upward with maddening slowness, "The time before that."
"But I mean it this time," Edward pleaded, tone long since faded into something undignified. "I swear I won't ever—ah—won't ever—ahh—dammit, Al, let me talk a second. I can't—" But whatever he couldn't do was lost in a yelp, and the boy's hips jerked up sharply once, twice, three times, coherent speech fled completely in the face of sensation.
"Brother," Alphonse said sternly, tracing a slow trail over the spot that had provoked the best reaction. "You can't honestly expect me to believe you. I mean, really now. Be reasonable."
The sound that dragged itself from the older boy's throat was truly pathetic, a groan thick with need. Though he'd long since realized it a futile endeavor, Ed tugged desperately at the straps binding his hands above his head, too far gone already to so much as wonder, as he had during the first hour of the torment, what material his brother must have transmuted the bindings into to ensure that they held his automail limbs.
"Please," he panted, when he could speak again. "Please, Al—"
But the only response that Alphonse deigned give was in action: he leaned down with deliberate slowness, traced the path that the feather had just taken with his tongue.
The moan that wrenched itself from his brother's throat was low and wavering, and hands that had only been flesh for a matter of months needed to hold the smaller boy's hips down to keep him still. Edward's pants became harsher as the seconds dragged on, unable to lay still under the assault but equally powerless to speed the agonizing pace with which Al seemed happy to torture him.
And then, abruptly, the sensation was stopping, Alphonse disentangling himself and pulling away.
He was halfway to the door before Ed had caught his breath enough for words.
"Al—" the smaller boy gasped, squirming fruitlessly against the covers. "Wh-where're you going?"
"Next time you go to dump out perfectly good milk," Alphonse advised him, smile the picture of innocence. "Maybe you'll remember that the payback isn't worth it."
The click of the door closing was drowned out by Ed's wail of despair.