@John415,
Are you gay? Whenever you are physically engaging in sexual acts (kissing, touching, etc) with the same sex, in that moment you are. Also, whenever you mentally think of the same sex for stimulation, in that moment you are.
If a "gay" guy has sex with a girl, at that moment he is straight.
Can you change what you are attracted to? If one understands how the entire process works well enough, you could make people get aroused by anything. What you are attracted to is due to your environmental exposures. When you understand this, you can understand why it is you are attracted to what you are attracted to, and, how you can change/control it.
So to answer your question. Yes.