Penis Plugs Urethral Insertions are the new ‘it’ in men’s sex toys. Over the past 20 years men have discovered that the nerve endings in the urethra are possible the most sensitive in a body and Urethral Toy Play has become almost common. The greatest challenge to anyone considering using penis plugs is the first time and being able to relax. The thought of inserting a medical sound into the eye of a penis is daunting especially for a novice but the rewards that you will experience once that cock plug is snuggly inserted are most often well worth it. Those that have experienced ejaculation when using urethral sex toys have described it as ‘cumming inside out’.