Question: Regarding (the husband) if he kissed his wife, or cuddled her and thereby excreted prostatic fluid, does that invalidate his fast or not?
A: According to most of the scholars, his fast is invalidated because of that.
– Ibn Taymiyyah, Fatawa Ramadan – Volume 2, Page 456, Fatwa No.387, Majmoo’ Fatawa Sheikh Al-Islaam Ibn Taymiyyah – Volume 25, Page 265