I love watching you on your fucking machine while your nipples are clamped. The expression on your face suggests that you are enjoying it immensely. Thank you for posting
try alligator clips like they use in electrical work. they are really cheap. they have teeth that will bite into your nipple. that may be too much, but there are other clamps at the hardware store that will work and be in your budget. i used the clips with the teeth and it gave me a rush of pain that i loved. also, have your lover put on your nipple clamps and then tie your tits tight. that will give your nips a rush. i would also use clothespins on my nipples and then a small c-clamp on the clothespins and tighten it down to the level of pain i craved.