Homosexuality (or really any sexual orientation) is not a transitory experience. So, in order to be gay it would have to be something that you feel more than just once--which can be attributed to human curiosity.
Whatever label you choose to describe your sexual orientation should be the one you feel best describes your feelings. There is no binary "straight" or "gay" check boxes to pick from. There is a whole spectrum of orientations including, but not limited to: Lesbian, gay, bisexual, pansexual, asexual, transgender, intersexed, questioning, and straight. Do not feel pressured to pick a label, stick to the "confines" of that label, or come out about a label you have chosen until you feel completely ready, comfortable, and safe about your choice.
*Different sexual orientations are part of the amazing amount of differences possible in humans. We should celebrate the fact that all humans are different.