Do imagining sexual scenes affect the validity of prayer and ritual purity, given the presence of prostatic congestion that causes the release of a few drops of urine, madhiy (pre-seminal fluid), or wadiy (a thick white fluid discharged after urinating) after urination?

One should not intentionally dwell on forbidden thoughts because addiction to them may lead to falling into what Allah has prohibited. Imagining such scenes outside of prayer does not affect its validity, nor does it if it occurs during prayer and does not prevent the performance of its pillars and duties, though the reward will be lessened. However, if it results in the emission of a discharge like madhi (pre-seminal fluid), then the prayer becomes invalid. To get rid of these imaginings, one must turn away from them and fill their time with the remembrance of Allah, reciting the Qur'an, choosing righteous company, and observing frequent fasting. It is recommended to sprinkle water on the area and trousers after istinja' (ablution after relieving oneself) for those who suffer from waswasa (obsessive whispering).