Must outer garments, prayer abayas, and other clothes worn after feeling pre-seminal fluid (madhiy) discharge be washed, given the presence of moisture on the exterior of the undergarments?

Obsessive thoughts should not be indulged. If what you felt regarding the discharge of madhy (pre-seminal fluid) was an illusion or a doubt, the default assumption is that it was not discharged, and that what came out were natural, pure secretions. However, if you are certain or highly assume that madhy was discharged, you do not need to change your clothes. It is sufficient to perform istinja (washing the private parts) and to sprinkle water on the area of the inner and outer garments that the madhy reached, if the impurity reached them. Purifying madhy by sprinkling water is the view of Ahmad, may Allah have mercy on him, because it offers ease. As for clothing about which there is doubt whether impurity reached it, the default assumption is its purity. Doubting the impurity of other clothes, such as the prayer abaya, is pure waswasah (obsessive whispering). It is obligatory to adhere to the legal hijab and the ample clothing for women that covers the entire body. Wearing outer trousers is not permissible according to Islamic law because it outlines the awrah (parts of the body that must be covered).