How long does it take before oral STD breakouts develop?

you're probably talking about herpes, oral herpes aka HSV-1, is a virus (can't really classify it as an STD, b/c it's not only transmitted sexually) that makes it's home in your nerves, and when you get an outbreak, cold sores and fever blisters break out around your lips, but not to worry, 90% of americans already have this virus, they've developed it when they were young, including me, i get a cold sore here and there every once in awhile, if you've caught it later on in life, through sexual activity, or sharing a glass, they'll be a little more intense, b/c if you caught it when you were young, your body is still building an immunity to it.