Touching the intimate parts of another person, even through clothing, is often associated with sexual intent. Thus, if this is done without consent (or with consent that is legally not valid), it may be considered to be sexual harassment or sexual assault.
In some societies, the human intimate parts are deemed sacred and are part of cultural rituals. For example, a village in Côte d'Ivoire considers female genital cutting a social ritual. ([1] (http://idcs0100.lib.iup.edu/~tconelly/Africa/Reading/SlowChallengeRitual.htm)). A routine cultural practice of male circumcision is still performed in most hospitals in the USA. In many cases, a sex reassignment is performed on intersex children. Some genital integrity groups perceive these practices as barbaric and violent.
An intimate or private part is a place on the human body which it is usually customary to keep covered with clothing in public areas, as a matter of decency.
In Islamic traditions, the definition of intimateparts are similar to their definition in Western culture.
However, exhibitionism is an example of a typically nonthreatening mindframe wherein the person who exposes his or her "intimateparts," particularly female breasts, is looking for a validating reaction from those to whom the parts are exposed, giving the exposer an ego rush and feelings of validation and attention.