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 manyour right.
when a gay or a homosexual has been single for a long time and haven't been in a relationship with another gay and they start to get sad over and and start dreaming of being gay with another
Person #1:Man I've been single for awhile! I want someone to be gay with!
Person #2 : Looks like you have gay fever.
Person #1 : Wow, I think you're right.