ANSWER:

No need to wash the pants if there are no traces of impurity on them. It is not radio active !

After emission of madhiy..it gets stuck on my underwear now i wash my underwear but nowadays i am having doubt that from underwear it is transferring to my pants and then on t-shirt..before i didn’t think about this and only wash my underwear and prayed salah..should i wash my pant and t-shirt also?i never wash my pants becz i didn’t know that wetness transfers