Energy play is a subjective emotional practice that frequently is said to have spiritual and transcendental connotations. Generally speaking the top will seek to stimulate a response from the bottom without the use of physical touch, though specific experiences may vary wildly.
Energy play is frequently said to include techniques of: muscle-tension/relaxation, hormonal or sensory stimulation through touch or imagination, emotional self programming, Endorphin manipulation through SM techniques to produce a chemical high, repetition, slight of hand/confusion, hypnosis and stress techniques to create a suggestible state for the willing, and use of cold reading and interrogation techniques.
Some energy players claim use of techniques that include more esoteric notions that include energy field projection, chakra manipulation and similar notions that are not scientifically verified.
It is important to note that science studies the statistically significant aspects that help us generalize and catalog concrete while spirituality embraces the statistically irrelevant and subjective aspects that make us individuals. As such we can naturally expect that well conducted skeptical scientific research shows absolutely no physical evidence of any "spiritual" energy fields that exist outside of typically understood and measurable forces and phenomenons; this has been the case regarding all topics of parapsychology since its inception in 1882 as parapsychology has never produced a single testable result in a double blind experiment.