Jenna had never been comfortable in her body. She was too heavy. Oh, she loved her shape, being full-figured wasn't the problem. It was all her internal organs and bones and muscles, and everything that could age and decay and take her further from her ideal shape.
She knew the fix, though: becoming a mannequin. Hollow plastic, light and perfect and unchanging.
There weren't many people who understood this desire, but all it took was one. A representative of The Mannequin Company found her, and a few days later she achieved her ideal form.
She can't do anything with her body now, and it's not even her body anymore given that she's property. But when her O loop kicks in, any niggling doubts that might have crept in are washed away in the waves of pleasure.