The sections on telling and when and to whom is more detailed in the Good News……
So if a person is the giver of oral sex to you, there is a small chance that could get it orally. If they did, it would look like a cold sore. If they already have a history of cold sores, they would not be able to distinguish an oral HSV 2 infection from a cold sore. Also, it would vaccinate them against getting genital HSV 2, in essence. HSV 2 orally recurs and shed infrequently.
I would just try to become aware of prodromal symptoms and avoid sex when you have a those. You can clearly identify things that are less subtle. And remember that there is only so much you can do. Some shedding is completely without symptoms.