Thanks for your question. Acyclovir and valacyclovir are used to treat herpes and it is valacyclovir only, which is used to prevent transmission of virus between partners and not acyclovir. But there is still a possibility of getting infected when herpes virus in the particular person become resistant to acyclovir. In some people, there will be no visual signs of outbreaks which don’t mean that they are not infected. Even a single unprotected sexual intercourse can make a person infected. Anyway, in your case it is unlikely to get affected with herpes as there are no visual signs of it. There is just a 10-20% chance to get infected if the carrier has got infection. Hope my answer helps. Take care.