What are the chances of giving a man who's got no STDs my herpes virus or antibodies?

Genital herpes. Genital herpes can be transmitted during sex even if no visible lesions are present. Barrier contraception ( condoms) can reduce, but not eliminate, risk of transmission. Risk can be reduced further with suppressive antiviral medication for the infected partner. Your doctor can prescribe this. Your partner will produce his own antibodies if he becomes infected.
Very good if lesions. If you have active blisters (lesions) present, then unless your partner has antibodies and immunity to herpes, he can contract the virus.