He will react like any other dog.
So that means it is completely individual.
Most dogs are ok with it if you are doing it correctly and they trust you.
Oral sex it more or less about masturbating a male dog with the added benefit that in the end you do the masturbation with your mouth. So lets begin with how to masturbate a dog. Castration/neutering: The purpose of castration is the removal of sexual behavior. "Another benefit of castration is...