It is literally impossible for me to have transmitted any STD to my wife as I can honestly say she is the only person I've ever had sex with. But now that were in the middle of a divorce, she is now claiming she has an STI and that I gave it to her. I'm am going to go get tested tomorrow. However, since I know I've never been with anyone else, if I now test positive, she had to have been the one to give to me, but how would I prove that?