cold sores are caused by the herpes simplex virus (specifically hsv-1). once you're infected with this virus you have it forever. however that doesn't mean you'll be broken out in cold sores all the time. the virus can lie dormant for years and then cause sores to erupt unexpectedly. as to who's the culprit between you and your girlfriend in terms of who shared the virus it's impossible to say. you may have gotten the virus when you were a baby but never had an outbreak and then passed the virus to your girlfriend. or she may have had the virus and has now passed it to you. either way if the two of you have been kissing while one of you has a cold sore it's a safe bet you're both infected. so what does this mean? well in a certain way not much. like i said a large number of people are infected with hsv-1. on the other hand you each must be careful never to kiss the other's genitals when you're experiencing an active cold sore. this can actually cause the other person to get genital herpes (hsv-2) which is an incurable sexually transmitted disease. it's also annoying and can be embarrassing. people with genital herpes must avoid having any sexual contact during an outbreak. a condom is not necessarily adequate protection against hsv because it may not cover all the skin areas that can come in contact with a lesion. hope this helps!
i have never got cold sores but when i kiss my girl friend i get them. what is the reason behing this? . i have never had cold sores in my life but my girl friend has got them 3 4 times and it seems they happen whenever we kiss. what is the reason behind this. ? . i feel very sorry for what is happening am i the curlprit?