My wife and I both love clamping cloths pegs on our nipples, first we take it in turns to cuff the other behind while they are nude then on go the cloths pegs, even though we are very experienced it does not take long before the pain starts (we use plastic pegs with tight metal springs}
The pain is a nice erotic pain and we can have them on for up to 25 minutes each however we never wear them for any longer
Always after each session we have sex maily anal it is so good