His penis is becoming sentient as it grows

The voice echoed in his head as Andy felt his cock grow bigger, stretching his boxers to their limits. With a sudden jerk, it tore through the fabric, revealing his throbbing, veiny, green-tinted shaft.

He gasped, shocked by the sight of his own member. It grew bigger still, pulsing with each heartbeat, oozing thick green slime from the tip. His balls tightened, pulling up against his body as they began to swell, filling with the same mysterious substance.

Andy tried to stand up, but his legs were weak, trembling under the weight of his newfound desires.