HSV or Herpes Simplex virus is the virus which causes genital herpes in human beings. It is of two types, HSV type 1 and HSV type 2. Of these, HSV type 1 causes cold sores and facial sores. Type 2 HSV is responsible for sores in genital areas and generally for genital herpes. Both of them are transmitted through sexual practices including oral sex and cunningulus. HSV type 1 is notorious in some other sense that it can be transmitted to children from parents through kissing and oral secretions. Generally, herpes infection stays dormant in 80 % of the infected people. There has been a wide spread of this virus, since it was reported for the first time. Early diagnosis and prompt treatment are required to suppress a possible outbreak. It has become a major sexual health concern for recent decades. However, no treatment for herpes has been discovered till date to eradicate the presence of virus fully from the body. Thant means, once it is infected, it will stay in human body for a life time. Anyway, presence of HSV 2 can be used as a measurement of sexual activities in certain cases. Antiviral therapy is used as treatment for herpes and antiviral creams are used as cold sore remedies. Condoms and such barrier methods are not found to be effective in preventing transmission of virus. This is because skin to skin contact with cold sores can cause cold sore spreading and spread of genital herpes. The best preventive step is to avoid sexual contacts including oral sex with infected people. In your case, your fiancé might have caught herpes infection, if you have did unprotected sex. But blood test results need not show positive in all cases. This makes the test less reliable too. Emotional and physical stresses including menstruation can activate virus and cause an outbreak and can even lead to life threatening situations. But it is not seen to change life expectancy in human beings. Hope my answer helps. Take care.