Could there be a @trust to steal where if you take something from a sleeping person who @trusts you, it won't trigger the nightmare script for them?
Not sure if this would also allow the @trusted person to pickpocket/take things from you when you are awake, but in all reality it's very annoying to wake up to the nightmare script when it's just your mano or mona trying not to disturb you as they borrow your quickterm for a moment. I feel like a @trust could work very well here in this case.