Beg

You spend a minute working the stiffness out of your jaw. Then you look up at your sister.

"Amy - look, you've had your fun. I can't get loose, you've done a really good job of tying me up. Now let me go - please?"

She sits on the sofa and looks at you. You can see her eyes roaming over your body and you redden with embarrassment.

You daren't struggle. The crotchrope is wedged between your labia, crushing your clitoris against your pelvis. You know that the smallest movement might start you on the journey to another orgasm.

"Amy? Please untie me. If you untie me, I-I'll do your chores for the next month."

You can see that she's tempted.