What happens if i put a cotton swab in my penis's meatus?

Why on earth do that: You will scrape and damage the delicate urethral lining at the meatus. Some men have an ill-advised compulsion to intruce objects into there penile urethra. They then go to the hospital emergency room if object slips out of their grasp and gets stuck in the urethra. Please don't do it. This is not a sensible or pleasant form of masturbation.