Uniromantic

Uniromantic, also known as unianthroromantic, refers to someone who feels romantic attraction towards one person and one person only for advanced periods of time or perhaps one’s whole lifetime. This is a more specific form of greyromantic, in which one only experiences romantic attraction a very small amount of times in their life. Once one is attracted to someone they will not experience romantic attraction to anyone else. One will be attracted to this one person regardless of the their own or the other person's changing gender, sexuality, or appearance. One will be attracted to this one person for a long period of time and feels as though they will not experience romantic attraction to anyone else for the foreseeable future.

The sexual counterpart to uniromantic is unisexual.