“So what are you going to do to me?” Sarah asked.
You smile and say, “Turn around and take off your shorts and panties.”
“W-w-what?!” Your twin stammers.
“You heard me,” You smile. “You said I can breastify one thing about you and I know what I will be doing.” Annoyed but complying your twin Sarah turned around and slipped off her panties and her shorts.
“Happy?” She crossed her arms.
“Yes.” You reply before you aimed and pulled the trigger. Right at the end of her tail bone a small stub grew out. As it grew out there was a small little nipple that grew out on top of the breast.
“Hey what are you doing?” Sarah asked you.
“You’ll see,” You smile as the breasts grew at a very fast rate as it grew past the size of a beach ball. You grinned while the breast doubled in size. “Once I am done.” The breast with the pink nipple continued to grow with her breast tail. Her breast got rounder as ballooned out. Soon it was bigger than 3ft round. You grin while your sister started to get a panicked look over her face. Once it was at the desired size, you let go of the trigger to see the giant breast with its pink nipple.
Sarah went slack jawed at the sight of the giant ass breast behind her. Flesh blocked her entire view, her new breast was just as round as she was tall.
You slipped around the giant breast and looked at your sister’s slack jaw. “So, what do you think?”
“WHAT THE HELL?” She snaps. “I can’t even move!” She gestures as she tried to walk but her giant breast tail weighted her down.
“You said I could do anything,” You grin at your shell-shocked sister.
“I did but…” Her eyes were wide. “Do you have how much fucking milk is in here?” She shook her breast tail for you to hear a little bit of sloshing.
You cover your mouth to hide a laugh while your sister snapped. “Not funny!”