In the throes of insatiable curiosity, a lone explorer takes their cock-play to new heights, delving into the world of extreme urethral insertion. With a gleaming metal sound in hand, they gently push the tip against their urethral opening, feeling it give way as they slide it deeper. The sensation is unlike anything they've experienced before, a mix of intense pressure and forbidden pleasure. As they work the sound in and out, they can feel their orgasm building, culminating in a explosive release as they withdraw the toy, their urethra ejaculating a thick stream of cum onto the waiting floor below.