Please note: This is written from the perspective of a male dominant. It also makes a distinction between a slave and a submissive with a slave being a little more, for lack of a better word, extreme. I guess I depends of how much of a slove they really are. If it is really supposed to be a punishment should the slave enjoy it? If a slave likes being spanked then is spanking really a punishment? Could not being spanked actually be worse then being spanked? If a slave misbehaves on purpose, trying to earn a punishment; how are you supposed to punish them? If they are not really a slave but rather a submissive or sometime submissive then should the punishment be different then if they were a slave? If they are submissive then it could be argued from the dominants position that the sub should enjoy the punishment a little... If a sometime sub enjoys the punishment then I think that would make them more likely to want to be submissive again, and more often. That would probably be good from the dom's point of view. The sub would want to be a sub because only as a sub could they "earn" more such "punishments". Here are two examples of similar punishments I thought of while I was bored at work. For the Sub: If she's normally a 1 or 2 orgasm girl the "punishment" could be for her to be restrained and have to "suffer" multiple orgasms from a bullet vibe while wearing an anal plug. For the Slave: If she's shy she could be made to give oral sex to her master in a semi public place while being teased with a bullet vibe but not allowed to orgasm while wearing an anal plug. And she must swallow.