"Damn. I'm startin' to feel a little funny."
Dan said nothing. He was lying back on his bed, staring at the ceiling, still thinking how cool it would have been if the spell had worked.
"Your A/C broke or somethin'?" asked Ian, lifting his baseball cap to wipe his forehead, which was suddenly damp with sweat. "I'm burnin' up in here." He replaced his cap haphazardly and tugged at the neck of his T-shirt, unaccountably tight.
Dan grunted non-commitally.
"Seriously, dude," said Ian, kicking off his soccer shoes and standing up, "I gotta get a Coke or somethi—whoa!" Ian flailed, trying to regain his balance, but overshot the desk as he reached for it. The chair went skidding back into the bed—making Dan suddenly sit back up like a startled jack-in-the-box—as Ian kicked out, finally catching himself by grabbing the bookshelf on the wall above.
Ian looked down and it was immediately obvious why he'd lost his balance: he was about a foot and a half taller than before! The hem of Ian's T-shirt now dangled far above the waistline of his pants, a whole six-pack of abs had been added to his suddenly elongated torso.
"What the—?" Ian pulled up his shirt somewhat dazedly, unable to comprehend what he was seeing, trying to understand how all that could be one body, his body.
Dan's mouth hung slightly open as he watched Ian's body lengthen even further, three more pairs of muscular ridges appearing on his stomach.
Just as Ian's head was about to brush the ceiling, he suddenly let out a loud moan and clutched at the sides of his torso. There, just below of the hem of his shirt, his sides suddenly began to swell with muscle, and Ian wavered, shuddered, and began to fall.
Dan watched it happen in what seemed like slow motion, one long fluid movement, as two limbs burst forth from Ian's sides, thrusting forward, twisting with muscle that eventually formed into the familiar shapes of Ian's thighs and calves, perfect copies of his original legs, right down to the smooth tan skin and soft brown hair, and all the time Ian was falling, falling, but at the same time his torso was bending—almost folding—back at the joint of his new hips, as feet formed at the ends of his new legs to catch his forward fall, and then, just as they were about to hit the ground, a new cock suddenly erupted from between the legs, shooting out to an impossible length, wide, heavy, and already half-hard, decorated at the root by a thick patch of pubic hair above, and a pendulous pair of balls beneath.
The crash of Ian's front feet to the floor kicked time back to its ususal clip; everything on the desk rattled loudly and books slipped down from the shelves above.
Then, silence, filled only by Ian's ragged breathing, as his chest heaved and his cock swung heavily from side to side.
Dan, wide-eyed, dared not even breathe.
Ian suddenly grasped the base of his cock with one hand and slid the other under his shirt onto his muscular stomach. "This... fuckin'..."
Dan recoiled and sucked in a breath through his teeth.
"...rocks!" Ian spun around, or tried to, but stumbled, unused to having four legs, laughing as he recovered, finally facing Dan with a rock-hard cock and a glittering countenance.
"I... um..."
"Shit, dude," said Ian, letting go of his cock to flex his arms and feel his pecs—which had also grown through his transformation—through his shirt, "they never told me growth spurts could be like this!" He tore off his shirt, sending his ball cap flying, and grinned even wider at the torso that was revealed.
"You... uh... like it?"
Ian almost laughed. "Are you kidding me?" He bent down to look between his front legs, his cock jabbing him in the mouth. "Hello, back there!" he cried, waving to his hind feet. The toes wriggled in response. Ian laughed as he stood back up, a smear of precum on his cheek. "Dude, I think I've still got a cock back there! I gotta get these guys off!"
"I... um... what?" asked Dan, scooting hastily aside as Ian leaped forward, rearing up and then springing off his hind legs, onto the bed.
Ian rolled over onto his back, chuckling as he kicked his four legs in the air, and then let them fall. His hind heels fell to the floor beyond the foot of the bed with a loud thump. "Help me get these shorts off," he said as he grabbed his dick with both hands and began to push at the waistband of his Umbros with his front feet.
Dan slid off the bed and moved around to pull at Ian's shorts, trying to slow his brain to the point where he could think coherently. God, Ian's new cock was so huge... the spell! It had worked!—sort of. Ian wasn't quite a centaur... maybe Dan had mispronounced something. But... was it all that bad? Now... after years dreaming of getting into Ian's pants, he was pulling them down—down his hind legs—and, oh, yes, there was a cock there, too!
Ian, already jacking off his front cock with both hands like there was no tomorrow, let out a grunt when his equally huge hind cock sprung back from the elastic waist of the shorts and slapped loudly against the abs of his lower trunk. "Dude," he moaned, his head rolled back into the pillow, "give me a hand or two with that."
Dan reached forward hesitantly, desperate yet not daring to touch, when suddenly Ian's hind legs bucked, knocking Dan forward, and both Dan's hands grasped that giant pole.
Dan froze for a moment, feeling the heat, the rigid thickness in his hands, unbelievable and yet very, very real. Slowly, he began to move his fists up and down the huge cock, then faster and faster, matching Ian's hands on the twin cock just a cumshot away.
Ian was moaning, his front legs cocked, running his feet over the ridges of his lower abs, occasionally knocking his hind cock or Dan's hands as all four of his legs bucked with approaching orgasm. That was when Dan leaned forward to wrap his lips around his friend's hind cock....
and Ian exploded. Dan gripped tight to the cock in his mouth as Ian's legs and body bucked and kicked all around him, load after load pouring into Dan's mouth, shooting over Ian's torso. Dan thought for sure he would drown, as Ian's cum overflowed his mouth and dripped down the sides of his shaft over Dan's tightly clenched hands.
Slowly, the spasms died down and the volleys of cum became a trickle. Ian's front legs relaxed and slid out unflexed along his sides. But Ian's hind legs still held Dan in a kind of benevolent prison, Ian's hind feet locked together behind Dan's back.
"Dude... that was sweet..." Ian managed between ragged breaths, his muscular chest heaving as he let his front cock fall against his cum-splattered abs and stretched his arms out wide. After a moment he propped himself up on his elbows and grinned down at Dan.
Dan nervously let go of Ian's cock and tried futilely to wipe the incriminating evidence from his lips.
But all Ian said was, "Thanks, dude."
"You... uh... don't mind?"
"Mind? If I'd known—" Ian suddenly broke off and laughed. "—we coulda been doin' this long ago. Well," he added, smirking and hugging Dan tighter with his hind legs, "not quite like this."
"Uh, Ian?"
"Yeah?" Ian, now out of the haze of arousal, was surveying his new body with obvious pride.
"I've... got a confession to ma—"
Before Dan could finish, Ian's cell phone rang...