Well as soon as I say it, it will happen, so if it does it's your fault
From one of my BPs, never. By my Children's Python, more times than I can count. From a 10 ft Burmese once and it HURT, dang thing had been missing for 2 months in the petstore I worked at and I was the one to find it. Hungry, right by the rat bins. It latched onto my hand, wrapped around my arm and would not let go!