"Oh! You're finally feeling the itch, right? I'll scratch it in a sec, but I wanna see your reaction first."
You gulp. Chalcedony's interests were usually grim. Nonetheless, you scraped at your skin- and felt it slip away, something wet and solid underneath. You almost retch.
"Ta-dah!" Its hand leap to your back, prying the rest of the skin away in smooth, practiced motion. "That's your chitin layer growing in, love! Its a shame its not a full body molt. But wait until you see the mouths we have hidden under here!" It's stroking your (attached) skin- another organ you're soon to lose, you suppose, trying to fight back the bile.
You can't hold it in. The first stage of modifications were so much on there own, and now this- you wanted it, but it was so hard. Instantly, its holding you tight, shredded flakes of skin forgotten.
"Shhh. There there baby. Its going to be okay. I know its gross, but you're gonna be so pretty for us. Now lets get you cleaned off, the fluid in there has been sitting in that space for a bit too long."