A man and a woman who are friends may avoid physical intimacy to avoid associations with sexuality (for example if one or both have a relationship with someone else).
Physical closeness may also be unvoluntary, as in a crowded train or elevator.
An intermediate form of voluntariness is when one goes to a crowded place for entertainment: a bar, disco, pop concert, street festival, etc.
International Hug Day is on 4 December.
Physical intimacy between a human and an animal may involve petting (caressing), hugging and playing.
Also a person, especially a child, may caress and hug a teddy bear or doll. There are also sex dolls, as a surrogate for a person.
Other kinds of intimacy are: