You have a surprise for her

You look down at Grace's come spattered face, feeling as powerful as you've felt in years. You step back from her, tucking your cock away and doing up your pants as she slowly gets to her feet, her eyes never leaving yours. You note that her nipples are stiff and hard, and that her pale skin is flushed with excitement.

Sally still sits on the bed, her face a mask of disgusted horror as she stares at her sister. You have no doubt that she is genuinely shocked by what she has witnessed, and that thought starts your excitement building. Grace bends down to pick up her discarded shirt, but you stop her with a barked command.

"You aren't finished missy!" you tell her. "You got your sister out of being punished, but you still have punishment to take." She looks at you with wide eyed shock, her chin trembling.

"But...you...but you said...." she stammers, fighting tears.

"I said I wouldn't punish your sister. You still have some coming."

"But...but...I sucked your cock!" she wails

"To get your sister off the hook. Now turn around and bend over. Put your hands on the bed," you order, picking up the hand mirror and smiling cruelly at her.