The family slowly worked its way towards the exit, finding cover inside zoo buildings or behind attractions whenever workers approached. Eventually, the family made it to a quiet building looking out on the park exit.
"Almost there everyone! Just a short sprint and we're out of here!" Robert exclaimed.
"I can't believe it! We're actually going to make it" Stella followed.
As the family prepared to make the last run, they were interrupted by a puff of air nearby. Stella and her children looked around in surprise at the sound before their eyes settled on Robert.
A shocked look was on Robert's face as he pulled a tranquilizer dart from the back of his jeans. His shocked gaze then shifted downwards towards his crotch as he watched a swelling erection begin to build in his pants. The family, not wanting to lose their husband and father, tried to pull Robert toward the exit, but were only able to get so far. Robert could uttered a low groan as his previously slowly growing erection rocketed forwards in his jeans.
"Go!" Robert bellowed at his family. "Get the police and come back for-"
Robert never got through his sentence as his now enormous penis and testicles erupted seed through his stretched jeans. Seeing the explosion of cum, Stella and her children's protests died. The family watched as Robert's hands became paw-like in appearance, his nails extending out. Similar extensions could be seen in his teeth, as they became wolf-like in appearance. Robert felt at his teeth with his new paws before a second orgasm forced them to his swelling organ.
The aphrodisiac mixed in with the zoo virus attacked Robert's sensibilities. Instead of fighting the changes, he began rubbing at the tent in his jeans, stoking his changes. Feeling this encouragement, the changes accelerated drastically. Robert began spurting cum sporadically all over the nearby building as his wife and children watched in shock.
"You have to fight it Robert! I know it's hard, but please you must do it!" Stella begged her husband.
Instead of slowing the changes, however, Stella's words seemed to accelerate them. With a sound mixed between a yelp and howl, Robert ejaculated again. His penis shredded the front of his jeans, as a wolf tail burst through the back. His face continued to change, beginning to lengthen into a muzzle. Formerly flat ears became pointed and moved to the top of his head. This all occurred as repeated orgasms assaulted Robert as he continued to thrust his penis through the hole in his pants.
Stella, meanwhile, moved to push the children away from their father, preparing to make the run towards the exit. She stopped; however, when she saw her husband's spurting equipment begin to decline in size. She gasped when she realized what was really happening.
Robert began groaning as his balls pulled up into his body along with his penis as a vagina formed. With a last spurt of cum, his penis pulled into his body and was gone. Meanwhile, buds began forming inside Robert's shirt, with wet spots appearing at their ends. Before Stella could say anything, milk began spraying from the buds, soaking her and her children's clothes. Eventually, the swelling stopped and Stella could only look in distress at her now very feminine husband.
Robert's changes neared completion as his body shuddered, becoming lupine in appearance. He was forced onto his hands and legs as his face fully pushed into a muzzle and fur began enveloping his body. Before long, Stella and her children were looking at a wolf in their husband and father's clothing. The wolf quickly began pulling at his formerly human clothes, shredding them to pieces.
"See Stella dear. I told you escape was impossible didn't I," the zookeeper laughed as she emerged from a nearby room. "Get' em boy" the woman exclaimed.
Stella and her children got one last look at Robert's now ferocious face before running from the building.