I'm afraid to ask my partner if they have an std?

im not with this person yet, but i fear that they might have an std. i know its a good idea to ask, but what if they get mad? what if they have no idea but dont want to get tested? I am abstinent, and i will not have sex with them, but i am afraid that they will have herpes, although i have never seen any out breaks around their mouth, but i want to kiss them sooo baddly, but i am afraid to because they might have herpes. am i worrying to much? is it a bad idea to ask even tho all i want to do with them i kiss? thanks .