Gay or Bi or Straight? What's in a label?

Is someone who claims they are heterosexual automatically considered to be GAY or BISEXUAL if they have had one same sex experience?  

Does the sex of the person in question matter? If it's a woman who has had same sex relations is she a Lesbian? If it is a man who has had same sex relations is he a Gay man?  

We'll talk about these things and the idea of "labels" in general tonight on Offlimits!