This is gonna sound like a really strange question, but can an STD manifest itself after almost 9 years? Here is why I ask. Just over 8 1/2 years ago I had unprotected sex once with a woman I knew very well. She had just come out of a very long relationship but I believe she had about 7 partners up to the time we got together. As far as I knew she did not have anything. Anyway we had unprotected sex once, and that was it. I changed jobs the following week and I have not seen her since. During the following 8 years I have not had anything wrong with me health wise and no problems with my penis. I am now happily married and last week my wife and I had sex (unprotected) and 1 day later I developed a small (3.5mm) red 'spot' or 'mark' on the top head (glans) of my penis. It has not grown, it is flat, it does not hurt, itch or discharge anything and the skin is like the rest of my glans (only red). I wondered if I may have a slight abrasion as my wife was wearing pantyhose. However I also started thinking if it could be something to do with my one (and only) unprotected sexual encounter other than my wife. I know without a doubt that my wife does not have an STD as she was a virgin before we met and I know from her character that she would not be unfaithful. I would happily bet my life on it. Any ideas? I am really unsure as to what this red mark/spot could be.