That's how I got it from my fiance. Genital Herpes. He never had any symptons that I know of. He was the only guy I was with sexually and the second person I have ever kissed. I don't know, maybe I missed something because I was younger and naive maybe if I saw things how I see things now I might have recognized an outbreak
back then.
I can't give you any assurance. This virus is so sneaky. Your best protection are honesty and information (I think)- if want to minimise the risk of transmitting to your partner - and hopefully your partner is being honest with you too.