When does sex feel most pleasurable? That's right, it's when you're on the edge of the piston without the rubber, when you're about to ejaculate! There's no going back to that moment when you can only ejaculate… I will definitely use my best piston for that moment! In this work, this most exciting scene of sex—the high-speed, vigorous piston-like motion leading to ejaculation—is condensed into a single image. Highly recommended for those who want to achieve a timely ejaculation, and for those who want to watch a girl orgasm while being penetrated.