I have a boyfriend and I'm not disclosing my oral herpes.
What is your reasoning for not telling him?
It doesn't matter if he knows.
You should tell your boyfriend as soon as possible about your herpes as it can definitely affect him. It's not cool to lie and if he finds out you're lying then he could rightfully leave you.
I think after you have been with someone for a while, they should accept whatever they find.
He probably will accept it if you tell him directly, though there is a high chance he won't if you keep it from him. You are putting his health at risk and as he's your partner, you should treat him and his health with respect.