Is it obligatory to wash trousers if the madhy (pre-ejaculatory fluid) has come onto the inner garments and no external trace is visible, and what is the way to get rid of the rapid discharge of madhy?

"Madhi (pre-seminal fluid) is impure and nullifies ablution. To purify oneself from it, it is sufficient to wash the affected area of the male organ and to sprinkle water on the garment. If you are not certain that madhi has stained your trousers, then they are considered pure. It is legally impermissible to look at an attractive, beardless young man with lust. If you feel an unusual sensation when looking at some students, this is an indication of lust, which is forbidden. You must strive against your lower self and avoid this. If there is a need to look, let it be only as much as necessary and without lust, while lowering your gaze from everything that is forbidden to look at."