Machine Gun Masturbation
When you're so determined to finish, you keep going even when you're already done, like a fool.
He came like a rocket, but still kept going like he was trying to break his hand.
He told me he was done, but his hand wouldn't stop. That's machine gun masturbation.
He kept going even though he was covered in cum. 'I'm not done yet,' he said like a moron.