They didn't have to wait long. Whatever was happening to him began to happen again. Dustin uncurled himself, trembled, and raised his head up, bonking into the ceiling with the top of his thick slimy head and coating the support beams in mucus. He seemed to curse quietly.
Without much warning, the snail gurgled and went stiff, straining against his own flesh as he once again began to shrink and change.
Krissi climbed back onto the couch, removing her shirt and wiping away the snail slime and cum from her lower body, trying not to be completely grossed out. She made a face as she wiped away the slime from the couch cusion and looked over just in time to see Dustin going through another change. She watched in fascination as his shell shrank away, he regained an emerging bone structure, and he crackled and twisted into a new form. The deformed mass of a quarter snail suddenly sprouted a proper mouth again, which soon began to turn into a hardened beak, while his meaty skirt shrank back and he began to regain limbs. The strangeness of the creature crawling on the slime coated floor soon began to resolve itself and Krissi watched in amazement as a new being began to solidify.
Dustin let out a startled "raw!" as he began to sprout black and white feathers, his legs returned... bird legs... and his arm bones began to form into fluffy feather duster wings that seemed too small for his bigger body. As his neck stretched out wildly, the former snail stood up dizzily as a 2 metre tall ostrich.
Krissi giggled in delight and stood up to stand next to her man, now a bird, and helped him stand as he shakily got to his feet. He let out a confused "raw?" and looked over his fluffy feathery body.
"You're an ostrich!" Krissi said in delight. "You're a big fluffy ostrich! I love ostriches!"
She flung her arms around Dustin's feathery body in her post-slime nudity and giggled madly. They looked into each other's eyes and Dustin offered a slight obvious smile at the edges of his beak. He gave his girlfriend a peck on the lips. A literal peck on the lips with his beak.
"Awwww!" Krissi giggled. "Well, as long as you're all big and tall, why don't you go grab the towels from the bathroom and help me clean up your gross ass snail goo?"
The ostrich looked around as the rather disgusting slime trails and puddles from when he had been huge and nodded sheepishly.
"Go on!" Krissi slapped his feathery ass, making him jump. "Hurry up before you change again!"
The ostrich complied quickly, running shakily across the basement floor and nearly skidding into the wall from the snail mucus, and turned the corner to the basement bathroom. There was a squawk that seemed to climb in pitch suddenly, and a sheepish half-sized ostrich emerged much smaller and carrying a load of towels on his back.
"Oh geez." Krissi gulped. "Well, let's do our best here, okay?"
The ostrich chirped, nodded, and together they set down the towels, the shrunken down mini-ostrich using his long neck, and soon enough they had the slime down to a manageable state. The carpet was hopelessly squishy and damp though, so they tried to avoid it.
With a sigh, Dustin now sat on the couch next to Krissi and they waited nervously.
"What's happening to you, baby?" Krissi patted the ostrich on the head gently, and he leaned into her for comfort, resting his beak on her squishy breast.
"I mean, you're obviously still you, you perv." She giggled.
The ostrich opened his eyes and smiled again before closing them.
A sudden jolt went through the bird and he squawked in alarm, pulling back as he shrank down much smaller next to the girl. Krissi gasped and reached down for him, picking up a twelve inch tall ostrich on both hands and holding him to her chest. "Stop getting so cute!" She ordered firmly. "It's turning me on again."
Dustin looked past her neck and met her eyes, wagging his tail feather and raising his brows lustfully.
"What am I supposed to do with you?" She giggled. "Birds don't have dicks. And besides, you're too small."
Dustin hmmphed and squawked in a high pitch, making Krissi giggle.
"Don't pout." She scratched under his chin. "You already got to fuck me as a giant slimy snail."
The ostrich cawed and recalled... mating himself. He considered the sensations and the experience and started to feel a little... flushed.
"Well, I'll be damned." Krissi giggled again, grabbing the little ostrich by the body and raising him to inspect between his legs. Dustin squawked nervously and flapped his wings.
"Lookit that!" Krissi stared in amazement, probing a finger behind Dustin's lanky legs and touching a little red hook shaped cock.
The ostrich squawked and flapped his wings wildly for a moment... just a moment, arching his neck back and grimacing as he unloaded right then and there, spilling cum from the hole opening at the back of his dick onto Krissi's finger.
"Oh!" She drew back in surprise, watching the cock shrink back again and hole dribbling fresh bird jizz. The little ostrich in her hand panted and swayed dreamily. "Oh shit! Hair trigger on this body, huh?"
Dustin squawked and motioned down with his beak. Krissi stared, realizing what he wanted, and gave him a devious smirk.
"All right." She grinned, putting the ostrich between her legs and letting the little guy go to town. "Let's see what you can do, my little birdy."
Dustin's dark eyes lit up with joy and he sat down daintily, raising his neck and rubbing his beak on his girlfriend's giant clitoral hood. Using his entire neck and head how he would normally use a finger.
"Mmmmmm." She grinned, leaning back, putting a hand on her feathery boyfriend's entire back, and relaxing as he gave her a nice clitoral massage with the broad side of his tiny ostrich beak.
Before long, she was stimulated and in pleasure. Dustin felt the twinge again, gulped, and wondered which way he was going to go. As it turned out, it was bigger this time. Krissi suddenly had the weight of a full grown male ostrich on her and opened her eyes gasping.
"G-Get off!" She said hoarsely. Dustin complied, pulling back his long goofy legs and stepping back on the still damp carpet.
"Fuck," she cursed, "That was starting to feel really good."
The ostrich grinned mischieviously again, feeling himself rising from within, the scent of her pussy fresh on his nostrils, and grabbed hold of Krissi's hand with his beak. He tugged on her excitedly, and she giggled as he lead her off the carpet and behind the now destroyed TV, where an old matress sat on the floor. It was getting dark now.
With a playful pull, Krissi giggled as Dustin lead her onto the matress and let go, causing her to plop down and bounce the springs. He fell on top of her and began caressing her neck and chin with his beaktip.
"Mmmm..." Krissi kissed his beak appreciatively, "You smell like me and it's so hot."
She grabbed the back of the ostrich's head and let the big bird take her, wiggling into spread eagle as he caressed (and licked!) her big tits, crouching over top of her pelvis.
"That's it..." Krissi whispered. "God damn, you're just a horny beast, aren't you? I like you much better this way."
Dustin trilled and nodded, puffing his neck unconsciously, and put his weird hook cock forward.
Krissi moaned as it made contact and he slipped in. Dustin gave a few good humps, gasped sharply, and felt himself cumming, spewing cum from the base of his organ and pulling his neck back in orgasm.
"That's it?" Krissi deadpanned.
The ostrich looked down at her with a cockeyed 'challenge accepted' and a playful smirk at the edges of his beak. Instead of his boner fading he began pumping again, feeling himself welling up. If he were a full ostrich, he would have found his dick completely useless for human longevity, but the human within was still there and eager for some stimulation.
He lasted a full minute and a half this time, Krissi starting to sweat under him, before he relased only a trickle of jizz down her ass and found himself panting and sore.
The human girl giggled. "Well, I guess we know which bird is a sexual disapointment."
Dustin tried again but found himself too sore to go on. His dick felt like it might explode, so he reluctantly pulled back and tried to cool off while it quickly deflated. He felt so hot!
"It's okay, baby. I'm not mad." She consoled. "Just... uh..."
The ostrich opened his eyes and squawked.
"Uh..."
He didn't even feel the twinge this time. He was growing again! He watched in mounting alarm as he shifted size rather faster than before, quickly getting off of Krissi and watching his girlfriend and indeed the entire basement shrink down as he grew larger. A sudden kick jolted him back down and he found himself shrinking even faster, becoming little more than a grain of sand sitting in the middle of a giant matress. Another kick, he sprang back up and found himself face to face with Krissi.
"D-Dustin!" She cried. "You're..."
Another kick. The ostrich squawked in clear alarm as he surged bigger again, grimacing as he was suddenly a huge animal in a tiny space. In shock, he opened his eyes and found Krissi scrambling to get out of the way, realizing he was so huge that his beak touched the wall and his feet were crunched against his knobby bird knees.
He realized something was terribly wrong as he jolted again, shifting back and forth between drastically different sizes. Too much sex, he whimpered. His orgasms had... agitated something. Whatever this was. One moment he was as tall as Krissi, then taller, then up to her knees, then surging as big as the basement... bigger! He knocked over furniture, broke things, and helplessly shifted up and down from tiny to huge in quick bursts. He let out a pathetic call for help at a few inches tall, then found himself pressing against the the roof supports and straining them ominously. This went on for some time before exhausted, Dustin found himself panting in the middle of the utterly disheveled basement and holding steady for the moment. But that was only the start...