2. Hot chick who never seems to go out with anyone.
3. A female that you know you can't become involved with past the point of friendship. This may be due to having a boyfriend/not being interested in you/or too busy to be involved with anyone. She's like the real forbidden fruit. You can't have a taste of her.
Effectively a prolapse of the testicles.
Gay Guy: Please don't say anything...Well, I tasted her forbidden fruit last night and now I feel strange. I thought I was gay but now, I have no clue.
Emma: But he hardly ever has sex with anyone!
Sarah: I know, he's a real forbidden fruit