You are approached by your girlfriend who purchased a magical box that is supposed to grant any wish when opened. She doesnt believe its true so she lets you try it out and you wish for her to have bigger boobs. At first nothing happens but her breasts start to grow until she has to take her shirt off. At first she is mad that you would wish for something like that but grows to eventually like them. This leads to her giving you a titjob and dirty talking about her large breasts until you cum all over her chest revealing you wished to give her a huge cumshot all over her tits.