To stretch a girl out so that the more she struggles, the more she is stretched, you can use a self-tightening rig. This is for advanced users only. Do not try this on your own as if it goes wrong, you will remain totally helpless.

The self-tightening rig is made using two cam cleats, which are available from most boating shops or over the internet. Use a kind with a triangular plate, two cams and a steel loop acting as a rope guide. The rope goes through the rope guide and between the cams. You can pull it through, but it won't come back. For a bondage rig, run the rope through a steel ring between the rope guide and the cams. Tie a cord to the steel ring. You can pull on the ring to release the rope from the cams. This is your safety cord.

You will need a wooden frame, so you can screw the cam cleats in place. You will also need eight heavy duty screwable rings (also available from boat shops), two bungees say four foot long, about twenty feet of rope, and wrist and ankle cuffs.

Screw two of the rings onto the top corners of the wooden frame. Screw two more onto the middle of each upright, and two more on each upright at the bottom end. Fix the cam cleats onto the top end of each upright, just inside the screw rings, so the rope can run through the cams towards the screw ring.

The rope runs from, say a wrist cuff, up through the screw ring, down through the cam cleat, then down to just short of the bottom end of the frame when the cuff is as tight as it can go. The bungee goes from the middle screw ring, down and through one of the bottom rings, then up to the end of the rope. Make sure you don't forget the quick release cord. The bungee should be slightly stretched with the cuff as tight as it will go. Adjust the position of the rings to give the bungees the right amount of movement.

You will need short ropes, say two foot long, to attach the ankle cuffs to the fixed rings at the bottom end of the rig. Use separate rings from the ones the bungees go through.

To use the rig, the slave lies down with her arms and legs stretched out loosely. First fix the ankle cuffs stretching her legs as wide as you can. Release the rope from the cam cleat at one corner at a time and fasten that cuff to a wrist. Do not attempt to tighten the rope. There should be tension from the bungee, but the slave should have some freedom of movement.

Now you can start to play. With every movement she makes, a little of the rope will pass through the cams and she will be stretched a little more. You know how to get her moving! Eventually she will be stretched quite taut. To release her, pull the release cords to free the rope from one cam at a time, or simply unfasten the cuffs.

If you just sit there and watch, eventually she will not be able to help moving a little. After a while she might just stretch up into it, because that feels good. But then she will discover how tight and helpless she is. And in a little while, to her surprise, she will find that she can stretch just a little bit more. You need to have a lot of patience. Don't rush it.

Once again, do not try this on your own. Play safely! And never leave a bound slave on her own.