Bisexuality is romantic attraction, sexual attraction , or sexual behavior toward both males and females,    or to more than one sex or gender. The term bisexuality is mainly used in the context of human attraction to denote romantic or sexual feelings toward both men and women,    and the concept is one of the three main classifications of sexual orientation along with heterosexuality and homosexuality , all of which exist on the heterosexual—homosexual continuum. A bisexual identity does not necessarily equate to equal sexual attraction to both sexes; commonly, people who have a distinct but not exclusive sexual preference for one sex over the other also identify themselves as bisexual. Scientists do not know the exact cause of sexual orientation, but they theorize that it is caused by a complex interplay of genetic , hormonal , and environmental influences ,    and do not view it as a choice. Bisexuality has been observed in various human societies  and elsewhere in the animal kingdom    throughout recorded history. The term bisexuality , however, like the terms hetero- and homosexuality , was coined in the 19th century.
Predictors of Bisexual Individuals’ Dating Decisions
Bisexuality - Wikipedia
In simplest terms, a bisexual person is someone who can be attracted to more than one gender; but adults and youth who identify as bisexual sometimes describe themselves differently. Many bisexual adults have embraced the definition proposed by longtime bisexual leader, national speaker and award-winning activist Robyn Ochs:. This broad definition of bisexuality includes people who identify as pansexual, queer, fluid and other labels that suggest potential attraction to more than one gender. Yes, and some are.
Bisexual erasure or bisexual invisibility is the tendency to ignore, remove, falsify, or reexplain evidence of bisexuality in history , academia , the news media , and other primary sources. Bisexual erasure may include the assertion all bisexual individuals are in a phase and will soon choose a side, either heterosexual or homosexual. One reason for this is the belief that bisexual individuals are distinctively indecisive.
Interviews were conducted with men, recruited from a variety of sources in Chicago, who reported sex with men in the past 3 years. Behavioral criteria were used to establish groups of gay and bisexual men. We predicted that gay men, compared to bisexual men, would report more male sexual partners, more experience with receptive sex, and more tolerant attitudes toward homosexuality. The only reliable difference between the gay and bisexual men with respect to number of partners was that gay men were more likely to have had a steady male partner or lover. Gay men were more likely than bisexual men to have engaged in receptive sex, including unprotected receptive anal sex.