The doctor's eyes widen as he unzips the next patient, a shy, lanky lad, revealing an impressive erection straining against his boxers. "Impressive," the doc comments, "Let's get a closer look." He wraps his fingers around the boy's girth, feeling the pulse. The boy gasps, his cheeks flushing. The doctor smirks, "You're in top shape, son. Now, let's see if we can't get some... samples." He retrieves a nearby cup, winking at the boy, "Ever seen a porn mag, kid? Consider this a... physical activity."