A fully nude, slim 18-year-old boy, standing confidently under soft natural light. He is 5 feet 4 inches tall with a lean, delicate body. His skin is smooth, bright, and fair — almost glowing. His face is youthful and beautiful, with a high forehead, sharp and slightly raised nose, soft cheeks, and a faint trace of upper lip hair — no beard. His body is hairless and well-maintained. His penis is 5 inches long, semi-thick, and erect — naturally curving slightly upward, as if in arousal. The shaft is clean and well-defined, with a visible tip. His testicles are proportionate and hang loosely. The pose subtly draws attention to his arousal while keeping the body graceful and realistic. The background is softly blurred to emphasize the figure. Photorealistic, 8k detail, cinematic lighting, full-body frontal view.