A gay man or woman who has sexual play with someone of the opposite sex under certain circumstances thereby making them a "homo" who is "flexible." Not "bi" where they actively are interested in both sexes, but a person who is normally 100% gay who engages in sex or some sort of sexual encounter with someone of the opposite sex for various reasons such as in exchange for something, circumstantial timing, for fun, or out of boredom.
A Homo Flexible could be submissive lesbian who has a male dom, or a twink with a female dom. A Homo Flexible could be a gay man or a lesbian who sleeps with or masturbates an opposite sex friend out of pity or to console them. Needing sexual release, a Homo Flexible could be a gay or lesbian who grabs the first willing person to "take care of their need" even if the person is of the opposite sex.