Viral Infection on skin.Help!!!

I had sex with my girlfriend about more than a year ago and after that when i under shaved i had pimples there and on my legs too. I consulted some doctors and they did there own stuff but noone told me that what is that. Some said it's a viral infection and now it's more than a year and i'm still having pimples apears inn and off. And whenever i do sex with any of my girlfriends they start coming out. And now i am getting married in this year and i am ery much worried about my current condition. Please do tell me what to do.