I'll put links to the rest of my story in the comments. Summary so far: I'm an artist with a special gift: I can manipulate my girlfriend's body using a clay figure, which I made for an art project on sexuality. First I experimented with her breasts, and found that she accepts the change after orgasming. Then I gave her much larger breasts and – just for fun (my fun) – a cock. This is how her day went after those changes.
Summer walked offstage with a smile, and was pleased to see that her handful of male students were actually working. She pulled the front of her blouse down while shrugging her shoulders back, ensuring that another inch of cleavage was stunningly displayed. She wanted to ensure that she would keep her students' attention, since they were rarely as rapt as they had been that morning.
The men stood to attention almost immediately when she walked into the group. "I'm so pleased to see you all working hard," Summer said, touching each of them on the shoulder as she walked around, "That will make it a lot easier to get through today's practice." Each student she touched swallowed as he tried to avoid staring at her cleavage.