What will Melanie become?

A pretty kitty

It was only natural given the theme about what they were doing the John would want her sister to be similar to herself but also distinctive. The blonde girl moaned gasping as she felt her hermaphrodite sister penetrate her eagerly taking away her virginity and her humanity in one fell swoop. Her hands began to thicken and her breasts began to swell as she felt her whole body tremble with the sensation of fur growing in.

Her body was covered in a snow white pelt befitting of her new shorter and plumper form. She could feel a long tail sneaking up behind her moving to wrap around her brother's long fox tail. The siblings were now intertwined Melanie's face pushing into a small feline muzzle as she let John happily ravage her. She was becoming an anthropomorphic Digimon just like her sibling and as her ears grew long and started to twitch. The newly created gatomon couldn't help but enjoy the pleasure.

She felt her own clit expand and grew, soft spines forming as it rubbed between their furry bellies. It was too much with a sudden twitch she was spraying seed all over her sibling