Toffee Bullet
To grab someone round the neck with your arm in a hold, and make a fist with your free hand and rub your knuckles across their head back and forth in a scraping motion.
me - "would you like a toffee bullet?"
Friend - "mmmm yes, sounds nice"
me - proceeds to give a toffee bullet
Friend - "ooowwww!"
Friend - "mmmm yes, sounds nice"
me - proceeds to give a toffee bullet
Friend - "ooowwww!"