1. A pseudo-religious movement, satirical in nature, to convert heterosexuals to homosexuality (or bisexuality). 'Ex-straight' ministries, a retort to the notorious ex-gay movement, often turn common, negative issues about homosexuality expressed in fundamentalist Christianity around on their accusers.
2. One who identifies oneself as homosexual (or bisexual) after previously assuming and affronting a heterosexual orientation. Can also pertain to one that has consciously chosen, or made oneself homosexual/bisexual.
1. An ex-straight argument might be that conforming to heterosexuality is conducive to overpopulation.
2. Jack was always more attracted to other males, but pretended to be straight to appease his peers. After high school, he was openly homosexual.