Kims cum is making Alison grow.

By: GiantessLover

Over the next few days, you noticed a change in Alison. She has gotten taller, and her breasts have swollen bigger. After many many tests they cannot figure out what caused her late growth spurt. One day she ducks into your bedroom, standing a foot taller and sits with you on the bed. She smiles and kisses you gently, as she holds you close.

"Willy, I think I know what made me grow. I think it was your sister's cum. Now I have an idea in order to get even bigger. Big enough to protect you, but you have to hear me out."

You gulp, not sure if you will like the idea or not, but you go with her to the barn where your sister smiles down at the two of you.

"Well, why hello lovebirds. Here for another cum bath? I mean, I hear you STILL havent gotten the smell completely out of your room. Also, My Alison, you gotten taller"

Alison speaks up to Kim, you can feel her massive chest pressed against the back of your head as she holds you gently

"Ok Kim, I think your cum is what made me get bigger and I have a proposition for you....I will become your lover and grow so you can easily make love to me as much as you want in exchange for a few things"

Kim is shocked...she's had a crush on your girlfriend since she hit puberty. You cant believe your girlfriend is going to start cheating on you with your sister, but for some reason....you don't really mind sharing her. If anything the promise of a gentler, giant lover is slowly turning you on...

"What would those conditions be..?" Kim asked

Alison Smiled and spoke "First, you have to stop **** my boyfriend and forcing him to pleasure your massive cock"

Kim shook her head "Out of the question, I love playing with willy too much to give that up!"

Alison Countered "Fine, if you wont give it up, at least be gentle with him. You keep getting bigger but Will doesn't so you have to be gentle or you will hurt him"

"Fiiiine and the 2nd thing?"

"I want to get as big as possible, i want to see how big I can possibly get from your cum so even if I get bigger than you, you will not deny me your cum!"

"Deal....now.....lets get you bigger"

You look at your girlfriend and your sister....who are about to become the same size....