Person who believes in the gay stereotype.
''I have a friend who's gay. You wanna go on a date with him?''
1st person is being a gaycist because he automatically believes they will have something in common based solely on their sexual preferences.
"Grandma, what you just said left homophobia in the dust. Surprise! You're just a dirty gaycist."
"I hate fags so much that I wish they'd die slowly and painfully from multiple venereal diseases at once. I'm gaycist and proud!"
Guy #2: "DAS GAYCIST!"