Heteroflexromantic (or Elaromantic) refers to someone who feels romantic attraction to individuals of the "opposite" gender, or to gender(s) unlike one's own, but being flexible in this identity. More specifically, heteroflexromantic is most commonly used by women who are romantically attracted to men but occasionally romantically attracted to other women, and by men who are romantically attracted to women but are occasionally romantically attracted to other men, though it can be used by any gender.
Individuals who identify as heteroflexromantic may identify with this label only, or they may also identify as Heteroromantic. Heteroflexiromantic individuals may also identify as or be considered Biromantic (otherwise Multiromantic), however for some heteroflexromantics, their attraction to the same gender is so uncommon that they do not consider biromantic to be an accurate description of their orientation in most situations.
The Homoromantic counterpart of heteroflexromantic is homoflexromantic. The sexual counterpart of heteroflexromantic is Heteroflexible. Heteroflexromantic individuals can have any sexual orientation. Also a lot of prefixes can be added infront of the word, for example for greyromantic folks who are heteroflexromantic it could be "Grey-Heteroflexromantic".
The use of the word "Heteroflexromantic" has been there for a long time, it is unknown when the term was first used though. It is usually reffered as "Heteroflexible", even though this term is exclusively as a romantic orientation. It is also commonly called "heteroflexible-romantic". On one amino post, Heteroflexromanticism was defined as: "A person who generally experiences romantic attraction to the other binary gender but acknowledges and leaves room for instances of romantic attraction to people of the same or similar gender(s) as their own."
The heteroflexromantic flag was made my unknown user and on unknown time. The first usage of flag was on amino blog, but the creator didn't say anything about being the creator of the flag.
The second heteroflexromantic flag was made by DeviantArt user Pride-Flags on 3 July 2016. It is very similiar to the first flag, but it has panromantic stripe on it instead of the rainbow stripe.
Other flags use the heteroflexromantic heart with other combinations, for example: "Homoflexible Heteroflexromantic", "Asexual Heteroflexromantic", and many others.