Carmen figured why waste time finding people to change. She would use herself as as the subject. If the change wasn't what she was looking for she'd just climax herself again over and over till she got lucky.
It also helped that she had a toy to use too, she took Mark the dildo in her hand and gave the flesh colored plastic a playful squeeze at its base, watching it buldge slightly, and all three heads licked their canine muzzles in lustful anticipation.
Picking a bench she sat down, lifted her balls with one hand, placed the dildo against her concealed pussy. She gently pushed it enjoying the slow expansion of her pussy lips, walls gripping tightly against her boyfriend-sextoy.
One head drooled as she teased her womanhood. Tale wagging excitingly she spread her legs to push the dildo deeper and to better give across to her canid cock. Her free paw like hand gripped the pulsing leangth and began stroking at an even pace with her dildo thrust.
"Hello? Carmen?"
Carmen stopped her masterbation as she heard the voice echo in her mind.
"Mark? Is that you?"
"Carmen! Yes it's me! What happened? Last thing I remember was being your cock this morning, then I was being fondled real hard by something and passed out when I..."
Carmen took the dildo from her neathers and the voice stopped.
"Mark? Mark? Can you still hear me?"
Silence
"Wh-wait. Don't tell me..."
She shoved the dildo back in her dripping snatch
"...came, and now it feels warm and good all over." Mark continued.
So mark was still in the dildo, and it seemed he was only 'awake' when he was being used.
"Mark, do you remember being a odd sex ball this morning?" Carmen asked.
"Yeah, it was really of but I never came so hard in my life just before passing out."
"Well, that huge orgasim turned you into a dildo. I've been carrying you all morning. And now I'm using you..."
"Uhh, that's what feels so good! My whole body feels alive and bursting with energy!"
"Glad you enjoy it, but how can we change you back?"
"Same as before, just keep using me... Feels sooo good to fill you up babe..." He cooed to her.
"Say no more!"
Carmen began thrusting again, soft sentual moans echoing in her mind from mark as well as her other heads.
She continued to beat-off her own cock, sitting on th edge of her seat to better reach her pussy from under her leg.
"Oh Carmen, don't stop I can feel something... Something inside me! Carmen it feels like when you change..."
"Oh yeah baby? Make it big, make it real big..."
Carmen felt her pulse quicken in her cock, one head looked down to watch the pointed leangth grow longer bust by an inch or so. The knot swelling to softball size.
"Mark! Your changing me! Oh baby you should know, were playing a game. Biggest change wins right now..."
"I'm what? Like its not just random?"
"No, you made my doggy cock bigger! Keep going babe, make me big however you like! I wana win babe, I wana win!"
Carmen kept at a medium pace in her strokes and trusts, not wanting to peak to early in the change. Mark kept makeing sentual noises in her head, keeping her aware of his state.
As her masterbation continued her cock stopped growing, her belly however swelled in size till it was as big as a beach ball. It soon began to turn gray as she noticed her multiple breasts shrinking inside till only her top pair remained and soon swelled to match her belly, sagging slightly from their own weight and turning gray as the black hair receded into leathery hide.
Still she kept up her pace as the sound of groning metal caught her attention and she looked down.
Her rear now consumed the steel bench only its hair was slowly fading as graw overtook her gigantic ass.
With a thud her weight crushed the bench and she stopped briefly as she landed on the dildo, pushing it further up her expanding pussy and out her hand.
"Oh mark! Keep going! Make me bigger!" Carmen yelled! Her three heads servaied how growing body her feet bulked into a thick toed stump of a leg and her hands fallowed as thick finger bloomed around her canine cock. They struggled to reach over her bloated belly.
"I'm not stopping babe! I'm gona make you huge!" He cheered.
Carmen bent her powerful bulky legs squaring now to reached her hand up her pussy to finger her dildo out, serving only to arouse and stimulate herself further as the thickening digits fingered herself. Her pace kept up as her catchers-mit hand compleatly engulfed her undersized penis!
Her three heads got a good view of her final change as all their muzzles grew outwords into slender serpentine trunks and ears exploded into flappy gery ears and tusks jutted out from her three mouths, forcing the heads to adopt amore spread out position.
Carmen came at just that moment three fat fingers deep in her snatch, nine inch canid cock in her one foot palm spewing jizz into it, and all three newly formed elephant trunks raised into the air trumpeting her climax as she passed out.
Mark awoke from another mind blowing orgasim. Being smothered by his girlfriends expanding walls as he turned her into the biggest animal that came to mind. An elephant of course. He'd thought about wales sure, but with now water nearby he was afraid something bad could happen. He rubbed his head as the sun beat on his eyelids. Oh! He hand hands and eyes! He was excited to have a body again after just being sexual organs all morning.
He slowly opened his eyes shielding them with his arm. Oddly it did nothing to dim the light and he soon found out why.
As he woke he came to realize he had three different points of view! Each with a big gray thing smuged in between them! He instantly knew what had happened. Looking down at the heaving gray breast and bulging gray belly. He'd somehow fused with Carmen. "Carmen! We got a problem, I think... Carmen?"
There was no reply. Further more he had control of his body, standing up and seeing from all three heads. Where could Carmen have gone?
He then realized that standing at his full thirty feet of height he was holding something in his hand. Looking closely it was a 9in canid cock dildo, the knot at its base the size of a softball.
"Uh-oh..." He mumbled finally realizing he had Carmen's voice now, though a octave or two lower from his size.
"Uh, lets see..." He reached down to pull up his balls and ...
Found smooth leathery skin. Checking again he found the womanly folds of the female genital.
"Damn..." Make mumbled to himself, herself... "Least this makes it easier i guess..." She said to her own heads as she reached down to part her lips and carefully placed the small didlo between them.
"Um, babe? You there?" Mark asked
"Hmm, mmm, yeah hun? What is it..." Carmon cood back at her boyfriend in her usual sleepy tone.
[how the didlo works: the dildo can control the transformation but when not used time stops for whoever is in it. When the person using it climaxes they become the next dildo that the person who was just inside it takes over the users new body]