A
nocturnal emission or
wet dream is a spontaneous
orgasm during
sleep that includes
ejaculation for a male, or
vaginal wetness or an orgasm (or both) for a female. Nocturnal emissions are most common during
adolescence and early
young adult years, but they may happen any time after
puberty. It is possible for men to wake up during a wet dream or simply to sleep through it, but for women, some researchers have added the requirement that she should also awaken during the orgasm and perceive that the orgasm happened before it counts as a wet dream. Vaginal lubrication alone does not mean that the female had an orgasm.