This Bi - "Curious" Crap

Been meaning to vent on this for a while now..
What is with the term "bi-curious"? What does it even mean?
People tend to label females/males as bi-curious when they feel attracted to the same sex but have not actually engaged in any activity with them. By studying this definition, we can come to the conclusion that the "action" on behalf of the individual is what distinguishes them from being bi-curious or (fully) bi-sexual. This implies that a person is not actually bisexual until they have carried out an act with a member of the same sex.
So now that it is assumed that a person is not bi-sexual until the "act" with a member of the same-sex is present, we must look at the validity of this claim - is this assertion true or is it a load of crap?
A load of crap, is what I choose to vouch for. Let us apply this claim on a general scale when it comes to the topic of "sexuality". Is it true that a person's sexuality is not defined until they act upon their motivations? In other words, does it also hold true for a straight person that they cannot be considered as heterosexual until they have engaged in intimate behaviour with a person of the opposite sex?
Case 1 - An adolescent boy is attracted to girls but has not had the opportunity to date/act intimately with them. Does this mean that he is hetero-curious?
Case 2 - An adolescent boy is attracted to other boys but is private about this matter, as he is currently in a (sexual) relationship with a girl to hide his real desires. Does this mean that the boy is heterosexual until he actually acts intimately with a male?

This simply shows that an individual's sexuality is just that - the gender that they are sexually attracted to. Attraction does not necessarily require action. Some people may criticize this argument with the objection that you do not have to define your heterosexuality through actions because it is "normal" to be straight, and it can already be assumed without having to carry out actual actions. If this is what you truly believe, do not bother - You've already succumbed to their desires. There is no normal - Normal is what they tell you is the case.