What is the ruling regarding the emission of fluid after watching pornographic films, without masturbation or touching the genitals, and does it necessitate Ghusl if its characteristics do not conform to those of semen?

You must repent from watching movies. It is not permissible to try to ejaculate by pressing on the vulva, as this is a form of forbidden masturbation. Ghusl (ritual bath) is not obligatory unless there is certainty of semen discharge, based on the Prophet's (PBUH) saying: "And for semen, there is ghusl." If what comes out is semen, ghusl is obligatory. If it is madhy (pre-seminal fluid), wudu (ablution) is obligatory, and the body and clothes must be purified. If you are uncertain between the two, you may choose.