Mitch, inflating on his donkey girlfriend, was having (and becoming) a ball. The last few breaths into him had forced his linked hands apart. He bounced up and away from Karissa, now only attached by his member that could not be taken out so tight was it inside her. This wasn't what Mitch wanted.
How he wished he could more easily straddle his lovely girlfriend. He wished that he could be a large draft horse, big enough to do what he wanted. A few feet away, the amulet glowed. Mitch didn't notice until he began to change.
His arms and legs lengthened, hand and feet become hooves. His swelled body swelled even more to fit his desire to be a draft horse. His inflated chest changed but little as it became a barrel of horse chest. His face pushed outward into a long round muzzle, and his ears grew up and pointed. An inflated tail sprouted out behind him, a comical version of a long haired horse tail. Lastly, his member swelled to that of a horse's one. Karissa and Mitch gasped at how tight they became.
Mitch was now a large inflatable horse, easily dwarfing the small donkey below him. He quickly straddled his love and squeezed her tight to him. He started to pump, but only managed to stretch Karissa's hind legs out as they were so tight that they'd become one.
The pleasure was becoming intense for them both, Mitch still had the air compressor hose in his mouth and was still inflating. Nothing else mattered to the two changed people as they only thought of inflating and their pleasure from it.
It was then that...