Make her into a shapeshifter.

The thing is, you don’t necessarily have anything you want to change about Kelly. After all, part of the fun of her becoming your property has been how long you lusted after her. She’s amazing as she is. But it almost feels like a waste not to use your great powers for great perversions. You’re worried about what to do, until you realize you have the perfect plan. Kelly can see the look you have in your eyes, and smiles, waiting for your order. “Kelly, from now on, you’re a shapeshifter, able to change your body however you want without any limits.”

She clearly isn’t expecting that, and actually gasps. There’s no immediate sign that she’s changed at all, and you can see her thinking through what you’ve just done. Then, she looked down and her heaving bosom, and you both watch as her breasts grow larger before your very eyes. Then, as Kelly bites her lip, you watch her breasts continue to grow, until they’re larger than any pair of breasts you’ve ever seen before. She looks at you, eyes lost in lust, and moans, “I am so happy you own me.”

Before you can say anything back, she jumps you. Even though you own her, you don’t mind at all. The way she’s been becoming more slutty, more insatiably lusty for you, is nothing but a plus in your mind. She rides your cock in a cowgirl position, but this time things get weird. The entire time Kelly is trying out her shapeshifting abilities. Making her breasts different sizes, including so larger they spill onto your chest when she’s sitting on your cock, back straight. Making her ass larger, the better to rub against you while she fucks you. But the most effective is her new control over her pussy, meaning she can make it tighter or looser to squeeze your cock for everything she wants.

Honestly, you don’t even remember too much of what happened that night. What is clear is waking up the next morning in your bed, Kelly cuddling next to you in her original form, both of you sticky and sweaty from all the carnal adventures you’d had the night before. You almost want to go back to sleep, but a knock on your door makes you reconsider that. You get out of bed, throw on some pajamas over your naked lower half, and quickly walk over to the door. Opening it, you find your mother, looking at you like she never has before. It’s a similar expression to when she’s been upset with you in the past...but there’s something new there. Something you’re sure you’re the cause of. “Since I need to help you four times today, sweetie, I was wondering if you wanted me to help you cum this morning?”