Looking at him slowly change to a Jenny made him realise the stiffness in his joints was because he was changing into a Jack! The newly formed Jenny noticed his new smell and with a rolling of her eyes, turned her rear to him and lifted her tail. He lifted his face and rolled his upper lip and took in all the scents she had to offer. He suddenly felt his new and powerful penis slide from his sheath and begin to harden, slapping his belly until it was firm. She turned her long neck and looked back at him with expectation, when he realised he was on all fours and approching her with only one thing in his rapidly dimming mind!