Mark couln't believe it. Could it be that he was immune to whatever had transformed his friend Bryan (and whoever else!) into a sex-crazed dog?
Whatever virus or curse had tried to struck him has possibly failed 'cause of something in his body that could take a fight with it?
Mark shivered as he tried to believe what he told himself.
If he, or his immune system, could resist the transformation, then he could be something like a saviour if he could pass his immunity to others or already shapechanged persons... if...
Something was wrong. Something was very wrong.
While he was thinking about all the possibilities his immunity would grant him Mark was observing the transformed Bryan who was still licking his own balld with his long, leathery tounge.
Despite his immunity Mark was really turned on on what his doggy friend was doing. Arousal started to wash over his body once again.
Moaning and shaking slightly Mark had to put his hands on his semen-crammed balls which were covered in a slight fuzz of fur.
The sensation of his gentle touches made his half-transformed dick grow out of his sheat one inch.
Mark could smell his own precum and that only strengthened his arousal.
Bryan was still licking his fully exposed cock and not paying attention to his still nearly human friend Mark who was struck shivering between two worlds.
The doggy mind in Mark wanted to release itself, to shed the human skin.
The human mind in Mark wanted to contain the dog, to fight it, to supress it.
The wounderful scents of Bryans slick doggy cock made Mark's own penis rise further out of his furry sheat.
His hands trailed across his red, slightly pointed shaft and more moaning sounds escaped from Mark's half-opened mouth.
The doggy side won the battle as Mark grabbed his cock with both hands, rubbing them along it's whole lenght. He started to jack off like he never did before in his life and it feld incredible.
If Mark had ever possesed any kind of imunity against the transformation virus that spread itself like wildfire, he vanquised it in the second he gave in to his new doggy instincts.
While he was masturbating Mark's cock shaped change to a full black shepards member and fur started to creep over his abdomen, heading outwards from his sheat.
Mark's cock spew forth the last vestiges of his human mind and sperm far too soon.
The slick semen splattered Bryans dark furm, but he did not care as he was still sucking himself.
Mark's legs gave way to a new doggy set of furred legs and paws as he tumbled over, landing on his rapidly changing hands which were already turning into clawed paws.
Still moaning and experiencing the greatest orgasm of his life so far Mark's face pushed out into a muzzle.
Scents exploded in his head as his nose shaped change, too, and his arousal grew even more as he pushed it near Bryan's slick cock.
Immediately Mark started to lick his friend's balls and cock...