From allo-(“other”) +sexual. "Directed at or involving another rather than one's self" and "involving the other sex; heterosexual" are the most etymologically literal senses (regarding the latter sense, compare the structure of heterosexual), structural and semantic opposites of autosexual and isosexual. The sense "non-heterosexual" was influenced by (and had influence on) Canadian Frenchallosexuel.
2014, Nicole Wiesenthal, “What it means to be asexual”, in The Mirror, number Fall, page 19:
Gray-asexual [denotes] a person who is somewhere between 100% asexual and allosexual; they might only experience sexual attraction on very rare occasions, […]
2014 March 20, a letter to the editor of The Record, volume 116, number 20, page 6:
Sexual assault is alarmingly common, yet most victims still identify as heterosexual, cisgender and allosexual (the opposite of asexual) after the trauma. Being sexual assaulted did not make me asexual, […]
2005, Tom Cohen, Hitchcock's Cryptonymies, volume 2, →ISBN, page 58:
Yet we later learn that Diana Baring already knew the secret — whether being “half—caste" references being lower-caste with “black blood” (more than a racial marker) or being transsexual, homosexual, or allosexual.
2006, House of Commons Debates, numbers 27-40, page 1595:
Diane Bourgeois (Terrebonne—Blainville, BQ): Mr. Speaker, last month in my riding, Gaétan Lord won the jury prize at the Allostars Gala for his contribution as founding president of Canada's first centre for “allosexual” or queer youth, which offers support to gays, lesbians and young people who are unsure about their sexual orientation.
2013, Alan Wong, “Listen and Learn”, in Oral History Off the Record: Toward an Ethnography of Practice, →ISBN:
Throughout this time, I have been struck by the absence of racialized, ethnicized, and colonized (REC) voices in historical accounts of the local gay and lesbian community at large, and likewise the lack of allosexual representation in the narratives of the city's various ethnocultural communities.
(chieflysocial sciences,of sexual desire or activity) Directed toward or involving another person rather than (only) oneself.
2002, Mary H Burleson et al., “Sexual behavior in lesbian and heterosexual women: relations with menstrual cycle phase and partner availability”, in Psychoneuroendocrinology, volume 27, number 4, pages 489–503:
Allosexual behavior peaked during the follicular phase for both heterosexual women and lesbians.
2011 August, Susan G. Brown, Marites J. Calibuso, Amanda L. Roedl, “Women’s Sexuality, Well-Being, and the Menstrual Cycle: Methodological issues and their interrelationships”, in Archives of Sexual Behavior, volume 40, number 4, pages 755–765:
Allosexual behavior was positively related to libido, and negatively related to positive and "premenstrual" emotional factors. Autosexual behavior was predicted by libido and an energetic / creative emotional factor.
There are intense debates in the psychoanalytic literature as to whether the primary form of infantile desire is allosexual (directed toward the other — in this case, the mother, the source of nourishment, her breast, her milk) or auto-erotic.
1980, Federal supplement, series 1, volume 476, page 1330:
Dr. Conigliaro contended that the sharing of the same bedroom by a single parent and child of the opposite sex "could contribute to, or cause, an excessive degree of ‘allosexual identifications’, [where a child identifies with the parent of the opposite sex][…]"
1992 February, Aldo I Vassallo, Christina Busch, “Interspecific agonism between two sympatric species of Ctenomys (Rodentia: Octodontidae) in captivity”, in Behaviour, volume 120, number 1/2, pages 40-50:
[…] We performed 45 experimental confrontations with heterospecific pairs. Confrontations (C. talarum vs C. australis) included allosexual and isosexual encounters.
(LGBTQ) One who experiences sexual attraction; one who is not asexual.
2014 October 15, Z Colburn, “"A" is for annoyed”, in The Easterner, volume 66, number 4, page 8:
[…] that is par for the course of being any form of queer-identified. But it also allows allies and allosexuals (persons who experience sexual attraction) to push out asexual and aromantic-identified individuals.
2014 November, Krista Rhoades, “Asexual Awareness Week”, in Collide, number 22, page 5:
A chart of the Ace Spectrum: the different possibilities for asexuals, demisexuals, and allosexuals.