Nancy's breast grow to the the size of the room she is in and her tits are bulging out the doors and windows and cracks are forming in the walls.
You look at Nancy and look at the book and the power you now have you can play god with everything around you yo watch as Nancy breast strain against the house then you go outside the see her breast stick out of the window.
Then you look inside of the book for more spells but as you turn the last page the black smoke from before swirls into the air this time it it much bigger then the black smoke enters each of your tits and then they become MMM cups but as your breast grow your vast knowledge about every spell fills your mind with newfound knowledge.