Negotiating in scene
From wipipedia.org

Negotiating in scene mixes negotiation with play, especially in a D/s context.
In physical play, negotiating in scene typically consists simply of slowly moving toward more intense forms of an activity, checking in continually to see if you are approaching your limits.
In D/s, negotiation itself can be made into a scene. For example, a Dom can start out by giving the new sub a safeword, and then negotiate by interrogation. Often, the questions are ones where the mere fact of being able to ask such a question reinforces the power relationship.
Some sample questions for negotiating in scene:
- Tell me something that we can pretend is a punishment, but is actually a reward.
- I want you to name something that is within your limits, but which you don't really enjoy, and that I may use if I really want to punish you within a scene.
- What's the most submissive/masochistic thing you've ever done?
- How would you feel about me giving you orders to do something when I'm not around? (For example) Is it within your limits if I left a message on your mobile phone ordering you to masturbate to orgasm? How about if I left a message telling you that you may not masturbate at all until you see me again?