You surprise yourself this time and say; "I would love to!"
The giant woman smiles sweetly
"Good, dear. Now, first things first I need to go to the shop to buy some food."
You looks puzzled, as if such a huge thing would move!
"So, I'll need you to hold this for me."
This doesn't help you confusion as she isn't holding anything.
Then you start to feel a little dizzy. And a little full.
You stumble around a bit before falling on your butt. It doesn't seem to hurt as much as you suspected it would, and looking back you see why. Your butt is bigger. Much bigger. And still growing! That's not all, either, you're fattening up everywhere!
You start to panic as the pounds are rapidly added to your once slender frame. Your shirt quickly become to small for your growing breasts and stomach and tears off. Shortly after your pants tear, releasing you butt rapidly and causing it to wobble comically.
You sit there, immobile now, and still growing as your huge butt lifts you off the floor. Over your pudgy cheeks you see the fat woman, now much thinner and in fact, only chubby. She seems to be thinning up too!
After a few seconds the woman is as thin as you were, and you are a gigantic immobile fatty like she was.
She smiles up at you "I'll be back shortly dear, wait here!" and exits the tent. You can't even seem to move, as you're trapped in you own gigantic rolls of fat.