Romantic orientation is a romantic parallel to sexual orientation, describing a general pattern of romantic attraction, interest, or desire. For example, aromantic is a type of romantic orientation label.
Although not well-known, models similar to "romantic orientation" have been proposed multiple times by different people over the past century and beyond. Here are a few documented examples:
In 1864, Karl Heinrich Ulrichs, a German sexologist, theorized two separate components to sex drive: "tender" and "sensual," essentially making an emotional/physical separation that allowed him to specify types of bisexuality. 
In 1959, the American Bar Association made references to legislation concerning discrimination on the basis of "sexual or affectional orientation."
In 1989, researcher and educator Joel W. Wells used the phrase "sexual and affectional orientation." 
- Kennedy, H. (1997). "Karl Heinrich Ulrichs First Theorist of Homosexuality." Science and homosexualities, 26.
- Brooks, R. (2010). [https://academic.oup.com/jhmas/article-abstract/67/2/177/799715 "Transforming Sexuality: The Medical Sources of Karl Heinrich Ulrichs (1825–95) and the Origins of the Theory of Bisexuality."] Journal of the history of medicine and allied sciences, 67(2), 177-216.
- Section of Individual Rights and Responsibilities Newsletter, Volumes 1-5, p. 10
- Shively, M. G., & De Cecco, J. P. (1977). "Components of sexual identity." Journal of homosexuality, 3(1), 41-48.
- Models of Sexuality in Shively and De Cecco’s “Components of Sexual Identity” (1977)
- Wells, J. W. (1989). Teaching about gay lesbian sexual and affectional orientation using explicit films to reduce homophobia. Journal of Humanistic Education and Development, 28, 18-31.
- AVEN FAQ (2003)
- AVEN Thread: Relationship Definitions (2005)
- AVEN thread: How many are...? (2005)
- AVEN thread: The Aromantic Threads Index - History of the Term "Aromantic" (2012)