The only one who can answer this question in all honesty is you. A gay man can easily look at the body of a female and see that body as in fact "art". If the body is beautiful it will have erotic qualities to it and yet it remains in the category of "art".
A straight man can look at the body of another male and again consider that body as a form of "art". If you look at at the body appreciating the look or the artistic form again you are still in the realm of art. I don't remember the name, but back in New York in the 1950's there was a very famous artist working in charcoal who only hired very obese women. The artist would render these very large bodies on to paper and the art made this artist a very large sum of money. Her works sold worldwide. The erotic value of these extremely large models would be in the eye of the beholder, but again, the art work was really incredible.
If you see the body or genitals in a sexual way this is an indicator that exploration is what should be on your list. Many men appreciate and wonder about the body of another male, this is simply curiosity and does not necessarily in and of itself indicate anything more than that.
If you were to explore and find that you were not only able to perform sexually with a member of the same sex, but enjoyed it, you would then move in a legitimate classification from straight to at least bisexual. If your exploration determined that over time you found members of the same sex to be more sexually satisfying than members of the opposite sex you would then move on into the classification as gay.
Out of curiousity? Why does it matter? Unless you are planning on exploring your own sexuality it is a mute point. The other thing is that it only matters what you think and feel.
Sexuality is an exploration process and many people do not really find true orientation until they are well into adulthood because of societal pressures. Forget the labels, your better off. The only thing they add is pressure to be one thing or something else. You'll figure it out in time and applying pressure to yourself usually results in some bad judgment calls.
