Is what was discharged due to watching exciting scenes many or madhy? And is ghusl required, or is wudu' sufficient? And what is the ruling on this act in Islam?

The transparent, viscous fluid that is discharged upon thinking about lust is called madhy (pre-seminal fluid). It is impure (najis) and nullifies ablution (wudu). The penis must be washed from it, but it does not necessitate a full ritual bath (ghusl (definition)). A Muslim must fear Allah and lower their gaze from forbidden things, because they are steps of Satan, and they corrupt the heart and weaken faith. As for the ruling on sin, there is no minor sin with persistence, and no major sin with seeking forgiveness. Woe to those who persist in their sins.