Jill groaned into her pillow, but as the sting on her cheek settled into a warm burn, she realized there was another source of pain-pleasure back there. Sandy had pushed the plug into her ass and was holding it at its fattest bulge stretching her sphincter. Just as she was getting used to that surprisingly-not-unpleasant ache, her mentor gave the plug a tiny push and her asshole sucked it in and closed up snuggly around its neck. The burn of the bulge-stretch subsided, and she found that she actually missed it.
"Do that again. Please," Jill said. "I think I'm learning."
"With or without the slaps?" Sandy asked as she began to pull outward on the plug.
As Jill felt her butt-hole slowly stretch out to release the plug the pain ratcheted back up but this time-without the distraction of the
