While Jeff pondered, Emily began rearranging herself into a more permanent form. First, she bent her front chair legs backwards until her feet were underneath her exact center of balance. This allowed for her hands to become free to use, and use them she did.
Specifically by pulling Jeff all the way back into her seat and useing her hands to cup his balls, gently massaging them. Next she pushed her clitoris out, extending it until it slipped into her brother's asshole. Then she pushed the rest of her pussy up and around his front, sliding over his dick until her pussy lips were pressing up against the base of his dick. Jeff was now stuck, trapped by his sister as she hardened all unnecessary parts once again, keeping only parts of her hands, her clitoris, and the inside of her pussy human so she could continue to oleasure him.
The last thing she did was allow his arms to slid inside of her breasts until his hands poked through her nipples. Now from his wrists up to his shoulders, Jeff found that his arms were encased inside of his sister's boobs, wearing them like sleeves. Though they were fully flexible and didn't restrict the movement of his arms in the slightest, it was still a very... odd feeling. He could feel her warmth arround his arms, but it was comfortable, not sweaty at all.
"Heeheee yes! Now Jeff and I are one." Announced Emily excitedly. "Um, listen Emily. As much as I enjoy your happiness, I kind of need to use the bathroom."
"So go. Use me. Use me like your personal toilet. Let me handle all of your bodies precious waste. Just go and let me handle it all from now on. Even if it eventually makes you incontinent so that you have to rely on me, use me! Actually, please become incontinent as soon as possible. I want you to use me as if it wasn't even a question." While Emily was saying this, Jeff could feel her clitoris widen inside of his ass, and the odd sense of relief it brought as his bowels were forcably emptied. His sister quickly moved them over to the bathroom where she used the toilet for them. "See, no problem. So I will be handling all of your future waste removals. And I won't take no for an answer, or you can forget about ever moving your arms again."
Jeff felt her breasts begin to solidify, trapping his arms completely. If left like this, he essentially would become useless. Just a source of continuous pleasure for his crazy sister. The ball which her feet had become, and that had flattened to become their platform base rounded itself again as Emily started to move again, bringing them back to now "their" bedroom. There the book lay, all Jeff had to do was make an edit, but his sister definitely wouldn't let him make just any changes he wanted anymore.
"I know what you are thinking and your guess is right. I will let you use it, but the moment I see you start to do something I don't like, I will stop you, understand." Warned his sister. Her warning was made extra clear as he could feel her grip on his balls slowly start to tighten. Quickly he agreed to not do anything she didn't approve of. Satisfied, Emily released her grip and went back to the gental massage she origionally was doing. If Jeff was ever going to get out of this, he would need to trick her somehow, but for now, he decided that he wouldn't risk it.