If, as per the Oxford English Dictionary, the word “heterosexual” means “a person sexually attracted to the opposite sex” and the word “homosexual” means “a person sexually attracted to the same sex,” and we plug those definitions into your statement whenever you wrote “homosexual” or “heterosexual”, we get the following:
Zoltan: Does [a person sexually attracted to the same sex], with only desire or attraction, become more of [a person sexually attracted to the same sex] upon acting on the desire/attraction? Or is that person a [person sexually attracted to the opposite sex] with odd desires and attractions…who becomes a [person sexually attracted to the same-sex] upon indulging?
So are you asking whether a person who is sexually attracted to the same-sex gets a stronger attraction upon acting on the desire/attraction? If so, I don’t think so, although I can’t speak for all people who are gay/homosexual. At least in my case, the attraction was there and was quite strong many years before I ever acted on that attraction.
As for your second sentence, many gay people never were attracted to the opposite sex, so that could not apply to them. I also don’t have any idea what you mean by a person who is sexually attracted to the opposite sex (heterosexual) with odd desires and attractions. What kind of “odd desires and attractions” are you talking about? Now if the person is sexually attracted to the opposite sex and is also sexually attracted to the same-sex, such a person might be called “bisexual” which means that they are attracted to both sexes.