He did not understand what she meant, until she turned round ..., slowly lowering herself directly towards his hardness.
"Don't you dare do it too quickly," she told him. "If you're not half as good as my vibrator you'll be in serious trouble."
She reached down, grasped him in one hand and guided him into her, sliding all the way down his throbbing hardness until she sat right down on him. She closed her eyes.