I’m male 36. There is a woman with whom I have sex occasionally. She says she is std free and she has shared her test results with me. I have also got tested a few times after I had sex with her and the results are all negative (just the standard std tests). However whenever I give her oral sex, i.e., my mouth is in contact with her vaginal fluids, I get severe fatigue and brain fog for several days and sometimes for weeks. Also the skin below my eyes becomes darker. The symptoms go away by themselves after some time. The first time that this happened to me I had some white patches on my tonsils as well. But the subsequent times I only had the other symptoms. I’m am very confused about what can be the reason for my symptoms. Is there any std that can cause this? If this is a viral infection like herpes and I was infected once, why do I keep getting infected again and again? Is this dangerous and should I stop having sex with this person?