I have read many forums and watched many videos, but I can not for the life of me pop my male ball python. I am afraid I am going to hurt him. I am trying to practice for when I produce my first clutch, but there are no breeders near me who can show me how to correctly do it in person. I am holding him directly under the cloaca, and rolling the tip of my thumb from the mid section of his tail up to his cloaca, but I can't get anything to pop out. Is there anything I am missing here?