We had a play over the weekend - a chance visit to Staples triggered it, of all things - and we came up with a simple DIY solution to this.
We were there getting some special printer paper, and we noticed some of the large bulldog clips we'd previously thought might work. They were cheap enough for us to say 'to hell with the expense', so we got a few of them to experiment with.
We messed around with them to see how strong they were and whether they'd grip; they certainly do grip, the bondage crew might just have a rather unlikely source of alternative material. If fact they gripped too hard, and there was a sharpish edge that was uncomfortable.
The sharp edges we got rid of with sandpaper, and by using some little bolts and nuts we came up with something that meant we could control how far they closed. By making it so there was still a gap left when you let them close, when they were on they would hold on to the labia just enough to allow them to be pulled with the clips, but not enough to hurt. We found that by putting a bit of silicone rubber edge protector stuff (looks like rubber tubing with a slit along it, we got it from a DIY shop to put on the sharp edge of some metal shelves) it was even grippier and more comfortable.
We then tied some lace through the holes in the 'handles' of the clips, and using that PVC bondage tape, we held the lace with the bondage tape wound round the tops of the thighs. When Mrs Belle spread her legs the labia would be pulled open, and after some experimenting she found she could control the amount of tension on the labia.
No prizes for guessing what we did after that!
Anyway, thought we'd share the idea with you all - happy experimenting!