You cant catch it twice you have it . You must be talking about outbreaks. You can get the herpes slimplex 2 (genital herpes) as a second contamination if the person has this type of herpes also.
outbreaks, meaning you will get a sore that will eventually heal and go away and then later return in the same spot. This is all caused by the same virus and the same infection. It is not a new infection just because it went away and came back. It is possible that if you perform oral sex while she is having an active outbreak that you could possibly infect a second area around your mouth, but it's always best to avoid sex when she (or you) is having an outbreak.