Jenny held her legs closed as tightly as she could.
"1...2...3" she counted. Almost on cue her pussyfied sister began to scream. Even though it was muffled the scream was still loud enough to be heard downstairs and the vibrations in her crotch were enough to make Jenny whimper. Eventually Emily quietened down and Jenny opened her legs again.
"Emily?" she said, "Are you OK?"
"Phat bitph!" yelled Emily, dripping juices as she fumed. "Phow thould she pho thish thoo me!?"
"Girls" called Martha from downstairs, "Breakfast is ready." the tone of her voice was as though nothing had happened.
As it was part of her curse to be unable to resist, Jenny walked back downstairs.
"Breaphasth?" asked Emily, "Buph phow am I phupposph pho eath?" then she remembered. "Pho! Phu can'ph!"
"Sorry Emily" said Jenny as she sat in her chair. Emily tried to protest but could only moan and grunt as the chair filled her up.
"You two look hungry" said Martha with a smile, "I'll plug you right in."
As she saw Martha finish set up the chair Jenny looked down at her futilely struggling pussy. The anger that had once filled Emily's eyes was gone, replaced by sheer terror at what awaited her.
Suddenly the brutally efficient started and the two wailed in pleasure as they came again and again.
After what seemed like an eternity the chair came to a halt. As Martha helped Jenny out of her seat Emily's exhausted and humiliated voice spoke.
"Phransform or phare."