Does the emission of pre-seminal fluid (madhy) upon watching pornography invalidate the fast?

It is not permissible to watch pornographic films because they are a type of forbidden fornication, as affirmed by the Prophet, peace and blessings be upon him: "The eyes commit zina (fornication) and their zina is looking," and by the words of the Almighty: "Tell the believing men to reduce [some] of their gaze and guard their private parts." What helps in abandoning this is supplication, keeping good company, marriage, or fasting. As for the emission of madhy (pre-seminal fluid) for a fasting person, it does not invalidate the fast according to the preponderant opinion, but it does nullify ablution (wudu') and prayer, and the male organ must be washed from it.