Heteroromantic

Definitions and Usage
A heteroromantic (sometimes shortened to "heteromantic") is someone who is exclusively romantically attracted to the "opposite" sex (for example, a man exclusively romantically attracted to women or vice versa). On its own, heteroromantic is not a part of the LGBT+ community, but it can be combined with queer identities such as transgender, asexual, or gray-aromantic.

Flags
Heteroromanticism is sometimes represented by black and white stripes (such as in the heteroflexible and homoflexible flags) but it has no official "flag" since it is not considered a part of the LGBT+ community.