What is the ruling on imagining engaging in sexual activity with males instead of females, knowing that the questioner is inclined towards males rather than females?

It is not permissible to issue religious verdicts without knowledge, due to Allah’s saying: "And that you say about Allah what you do not know." Allah has threatened those who do so with a severe punishment, and has even made it one of the greatest sins and gravest destructive acts, second only to associating partners with Allah. However, if a Muslim is asked about a religious matter that he knows, he may answer. It is not a condition for him to be a scholar; rather, he should attribute it to whoever he heard it from among the trustworthy scholars. As for sexual fantasies, they are forbidden if the one fantasizing is a male, because they are a means to committing indecency.