I've had this problem for at least 6 years now. Every time I have unprotected vaginal intercourse with a girl, she gets an assortment of major discomforts within 3-5 days, extreme itching, more than usual white discharges, minor pain in her vagina etc. This happens whether or not I ejaculate inside her. I myself have absolutely no symptoms what so ever.
I've come to believe there is something in my pre-cum that cause these symptoms in the female, If I have protected sex, she won't show have symptoms, if I only slide in a few times without a condom, she won't show these symptoms, and, strangely enough, all of my long-term sexual partners, usually after about 5-10 unprotected intercourses, will have these symptoms goes away, after using antibiotics etc. But a new partner will Always display these symptoms after the first few times and requires treatment, they are usually diagnosed with "vaginal uncleanness" or "yeast infection".
I have tested negative for any and all known STDs in multiple clinics, and I'm just stumped. If anyone can point out what this mysterious germ in my pre-cum that's causing my partners these extreme discomforts, you're obviously very very knowledgeable and I will be ever so grateful.
Thank you
Cheers,
Alex