Fruit Fly: a.k.a. Fag Hag
The Fruit Fly is a girl who is BFF's with a gay man. She goes to him for fashion and love advice, he goes to her for love and fashion advice. The Fruit Fly could at one point in time have a crush on the Gay friend and sometimes VV...but more than anything these two cosmic friends are friends...who drink and occasionally kiss each other and smack each other on the butt...and sometimes he admires her boobs.
As used in a sentence:
I have been Derek's fruit fly for about 16 years now. I love him, he tells me how hot I am, and he loves me and I tell him how hot he is in return.