You won’t be in line.

Is there no understanding among the poskim that the prohibitions of adultery (in thought) are only for a man on a woman? I remember a halakhic discussion in which it was agreed by threes that there is no prohibition on masturbation, and indeed, it seems that all the laws of modesty speak of the woman's body. And if the rabbi sees this as a prohibition, does he claim that the prohibition is sexual contemplations without any dependence at all on the object of contemplation? (An extreme example could be animals or even inanimate objects to which men of virtue are attracted)

Reflections on forbidden and naked grounds are forbidden reflections. Why would there be such a difference? Some have defined forbidden reflection as reflection that may lead to forbidden grounds.

Who are the ones who defined the prohibition only if it would lead to a forbidden cause?
And did their definition only refer to the Torah or did they also understand the prohibition from the rabbis?

I don't have time to search right now. See for example here:
https://ph.yhb.org.il/14-04-06/