I made the breathtakingly stupid decision last night to sleep with someone even though I suspected they had a cold sore. In the moment I tried to convince myself it wasn't, and that they would've told me if they had herpes, but now I'm kicking myself for not just saying no and leaving. Is there any possibility that if they have oral herpes, I haven't contracted it? Or is there any way of preventing it if they did? I know these are monumentally stupid questions, but I can't go to my GP unless I actually break out in sores, which I'm praying doesn't happen, and if my parents see me with a cold sore I'm done for. Is there anything I can do to give myself a chance of not catching it, or stopping the sores breaking out?