The term bisexual describes the disposition to be attracted to both sexes. The presence of bisexuality is higher among females. (LeVay, Simon and Janice Baldwin. Human Sexuality. p 166-180. MA: Sinauer Associates, Inc., Third Edition, 2009.)

A bisexual individual has the potential to be sexually/romantically attracted to more than one sex, but not necessarily at the same time or to the same degree. (Baumgardner, Jennifer. Look Both Ways—Bisexual Politics. p 41-60. NY: Farrar, Straus and Giroux. 2008.)

Bisexual men are often married and engage in casual sex with other males for variety. Bisexual women seek long-term relationships with members of either gender and are more likely to alternate partners. (Wilson, Glenn. The Great Sex Divide. p 86-87. England: Peter Owen Publishers, 1989.)