Everyone thinks certain things of the same sex. Questioning ones sexuality is human nature. Based on whatever prevailing circumstances get factored into a person's life, they'll make a decision of whether or not to act on their feelings.
It's entirely an objective view and homosexuality does not exist on a dichotomous discreet plane, but on a continuous one: a person is not either "straight" or "gay" - they just act in differing extents on their feelings. Everyone is at least a "little gay" or a "little straight."