In BDSM, the term mind fuck refers to the act of experiencing or creating a situation which brings about a sense of confusion or a heightened sense of stress, achieved by misleading someone within the confines of a scene or roleplay situation.
For example: A Dominant blindfolds a submissive and binds her to a chair. Then, the Dominant whispers into the submissive's ear "I've just invited all my friends over to watch me punish you." The "mind fuck" part of it is the fact that the Dominant has not in fact invited anyone over, but is just "fucking with" the submissive to heighten the experience.
What makes it even MORE of a mind fuck, is if the submissive has already led the Dominant to believe s/he is into having scenes in front of other people. This way, the arousal of knowing she may be in front of others is a positive situation and increases the excitement of the scene.
When one begins to have more experiences with mind fucking, one can easily be more creative as time goes on, creating different levels of stimulation and arousal.
A Dominant's purposeful use of the submissive's lack of trust towards the Dominant will prove highly effective, especially in the beginning of a relationship. Using mind fucks wisely and creatively can only help to build and strengthen trust and respect between partners.