Spearmint Shaft

In which Spearmint Magpie learns that there is more than one way for MagPi to rearrange her insides. Cock transformation ensues. A minific for a magpie.
Thumbnail art cropped from an image by BensterDiving
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When Maggie asked Spearmint if she wanted to have her insides rearranged, Minty assumed this meant a hard, heavy fucking. There's a reason that Mag referred to her horsecock as her breaker and, as Minty trusted she wouldn't be broken too badly, she took her friend up on the offer. Both of the magpies worked together to lube that heavy shaft until it glistened in the room's light.
Even with the lube, it was a tight fit for that thick, heavy cock to fit inside Spearmint's body. Mag planted one hand on the small of Minty's back to keep her in place as she fed inch after inch into the magpie's pussy. Rather than bottoming out against her cervix, however, the cock just kept going deeper inside her. Spearmint trilled in alarm at the unnatural sensation but Mag kept going. She wasn't going to break Minty, but she was going to break her in.
Spearmint was stretched to her limits. She could have traced the outline of Mag's cock through her body as if it was a part of her. She would have been half correct, though would have had the nouns backwards. Instead, she was becoming part of it.
Her stomach slowly turned from white to pink, matching the color of the equine penis buried within her. That hue spread steadily up her torso and down her legs as the transformation continued. Her waist swelled slightly as it became the medial ring for that heavy horsecock. Minty tasted precum as her neck turned into just a part of the cock's urethra; she was now freely drooling those fluids onto the bed.
Spearmint's appendages were next to turn. Her arms pulled down against her sides as they began fusing with the cock; within a few seconds, they resembled thick veins running along the upper portion of the shaft. Minty's legs pulled upwards as if she was nesting, then joined with her arms to continue those veins all the way to the base of Maggie's dick. Their prominence gradually faded and, instead, added to the overall girth of that fleshy monster between the bird's legs.
The tail and wing feathers were the last to go. By now, they were draped over the top of the shaft and vaguely resembled a condom. Those black and mint green feathers added a hint of color to the cock, making it darker on the top and lighter at the base. That too faded, with the only remaining hint of Spearmint's existence being a mint green tint on the mottling at the base of Mag's shaft. An onlooker would never have guessed that the bird's cock had a degree of sapience.
Despite being transformed, Minty could still feel everything happening to her. Her insides had indeed been rearranged, as promised; her entire body had become part of someone else's. Each throb of the magpie's pulse kept her dick hard and ready. The touch of Maggie's hands sent shivers through her body, echoing the movements of the bird herself. Mag sat on the bed and began to gently stroke Minty's body to give her new cock the full experience of being her breaker.