lubricating substance การใช้

• Saliva also contains mucins, lubricating substances that keep the teeth and mouth moist, and help with swallowing.
• Masturbation involves touching, pressing, rubbing or massaging a person's genital area, either with the fingers or against an object such as a pillow; inserting fingers or an object into the vagina or anus ( see anal masturbation ); and stimulating the penis or vulva with an electric lubricating substances to intensify sensation.