I need second opinion

Hi, my name is Chesok. I have been dating my boyfriend for 8months and we have had unprotected sex for all 8 months. He resently developed rush on his penis that would heal and come back again. We both went to the clinic and got tested for Herpes. I was negative and he was positive. He is fricking out and I am not. We are trying to get to the bottom of this, together. What doesn't register in my head is: how did he get it? If he had it for long time and never showed symptoms of this virus, wouldn't I have it too????? He is also married and I am suspecting his wife sleeping around, because he developed this rush two weeks after having sex with her. Do you think it's recent or he had it for many years and I just got lucky????? HELP HELP