You let Sally go

You smile down at Grace's happily satisfied face, then glance at Sally, still looking at her sister with a combination of shock and disgust. You notice that she's still gently squeezing her own breasts, her nipples stiff and rock hard.

"You're free to go," you tell Sally, picking up her shirt and dropping it in her lap. She looks down at it for a moment as unsure what it is, then quickly pulls it over her head. She stands up and takes a few steps towards the door, then looks back uncertainly.

"Aren't you coming?" she asks her sister plaintively.

"Go ahead Sally," Graces says softly, still curled on the bed and rocking gently. "I'll be along later."

"Oh My God!" Sally says in a quiet but extremely shocked voice. "You're going to do it again aren't you? You're going to let him do it to you again!"

"MmmmHmmm," Grace purrs, nodding her head as she squirms a little closer to you, looking up at your face with adoring eyes. "If he wants me. He can have me whenever he wants me." She bends her slender neck towards you, rubbing her face against your hand and licking your fingers, her eyes never leaving yours. You smile down at her, surprised at her complete submission, but enjoying every minute of it.

Sally takes another step towards the door, then turns and looks at the two of you.

"I want to watch," she says, biting her lip as though surprised by her own words. "If you're going to do it again, I want to watch."