Introversion: describing a shy, reticent and reflective person predominantly concerned with their own self, thoughts and feelings rather than with external things, attitude-type characterized by orientation in life through subjective psychic contents, manifested in more reserved and solitary behavior.

Also called introvert, intravert, intraverted and intraversion. And before anyone say, I know this is not a sexuality, but as an asocial extravert, my extraversion is like polyamory or a polyaffectionacy somehow, so this might be useful for those whose sexuality or romanticity is undefined or null (or a void-). – AP