I felt shy of asking about prostatic fluid from the Apostle ﷺ because of Fatimah. I, therefore, asked al-Miqdad (to ask on my behalf) and he asked. He (the Holy Prophet) said: Ablution is obligatory in such a case.
أَنْ أَسْأَلَ النَّبِيَّ ﷺ عَنِ الْمَذْىِ مِنْ أَجْلِ فَاطِمَةَ فَأَمَرْتُ الْمِقْدَادَ فَسَأَلَهُ فَقَالَ مِنْهُ الْوُضُوءُ