A person who identifies themselves as "straight" (not bicurious or bisexual) who, when horney enough, will have sex with the NEXT willing person, male or female. "Heteronextuality" is a condition, usually temporary, when a "straight" or "hetero" person is driven to have sex with a person of the same sex due to a bout of extreme horniness and the willing nature of the person NEXT to them.
So what if I did suck his cock? That doesn't make make me any les straight than you. A heteronextual maybe but never bisexual!
by JimTimH December 09, 2010