Rough nipple modification

My slave is here, in front of me, tied to the table. He knows very well that the time has come to suffer for my sadistic pleasure. I see fear in his eyes but my attraction is towards his tiny and tender pink nipples. They may be too small for my taste, but I know a good way to solve this problem and make them bigger, so that I can better them. After having position my new mechanism in front of his nipples, first, I'm going to pierce them with 10 cm. long needles, to which I will then attach my mechanism with a piece of twine that will allow me to pull his tender nipples and badly extend them. Now, after their nipples have been fully extended, it's time for me to start enjoying them in the most hard way, so that his screams will soon fill my dungeon. But I'm still not satisfied, my true excitement has just started and I have in mind another harsh that this stupid slave is going to discover very soon .....