“Sis stop! What are you doing to my tits?!” my “big” sister yelled at me as she reached her hands up to her ever shrinking breasts.
“Sorry, but I got tired of you lording your bigger assets over me. ‘Someday you’ll have big girls like me’ and ‘It’s hard having boobs like this sometimes.’ well I’m done! I slipped something into your breakfast this morning, and now your tits are becoming MINE!”
“Ugh! But I don’t want to have tiny boobs!” she shouted at me. “I want ones like you!” She smiled at my chest. The other half of the spell was starting to take hold: she was my younger sister now, and to her mind, that’s the way it had always been.
“Don’t worry, little sis,” I said, looking down on her for the first time in my life. “Someday, you’ll have boobs as big as mine.”