When a gay person develops feelings for another homosexual solely because they are gay. They see them as an option and subconsciously develop feelings because of this. Usually it wears of after a few weeks and is most common in young gays who are trying to figure themselves out and don't have as many open gays around them.
Gay: Hey man i heard Andy was gay, i think i like him.
Friend: No you just have gay fever.
Gay: shit man your right.