After a deep, sensuous kiss Fall pushed you onto the edge of the bed. You thought she might be planning to climb on top of you, but instead she sank to her knees in front of you and spread your legs. She fumbled with the button and zipper of your pants.
"I want to taste you so bad right now..." Fall muttered.
The feeling was mutual, but if your girlfriend was so eager to give you a blowjob you weren't going to refuse. She finally got your erection out and immediately went to work with her tongue. She'd never sucked your dick so enthusiastically before. You already felt yourself on the edge and tried to say something, but all you could manage was a moan of pleasure. Then you came, but Fall drank deeply. As you came, your hands went to her shoulders to brace yourself. You could feel your nails growing, claws gently cutting into Fall's shoulder, without drawing any reaction from her. You felt pressure at the base of your spine as your tail began to grow. The hair on your body began to thicken and darken.
Feeling you finally spent, Fall slid her mouth off your cock and flopped back onto the floor, staring at you with glee and licking her lips. She was still naked from your first wish. She slid a hand down between her legs and began masturbating as she watched you transformed. The changes soon became too much to remain seated and you dropped to the floor on all fours in front of Fall. Her scent was intoxicating.
You crawled the short distance toward Fall as your tail rose behind you and your ears became pointed. You tried to reach up touch her face with your hands, but your paws only came to rest on her breasts. Your legs shifted and reshaped until they were now your hind legs. Your features were rapidly changing from human to feline as you became the big cat of your dreams. Fall put her hands on your cheeks and drew you in for a kiss. Your face was the last part to change, but now you could feel it reshaping too.
"You make a magnificent panther" she said. "Now make me a cheetah."
You were eager to oblige.