fantasy
mental faculty of drawing imagination and desire in the human brain
sexual fantasy
mental image or pattern of thought that stirs a person's sexuality and can create or enhance sexual arousal
shipping
desire by fans for fictional characters (or more rarely, real people) to be in a romantic or sexual relationship
immersion
immersing in an artificial world by dissolving spatial boundaries
daydream
short-term detachment from one's immediate surroundings, during which a person's contact with reality is blurred and partially substituted by a visionary fantasy