Mark closed his eyes and laid his head back as the showers' warm water flooded over him, washing away the scent of the recent sex and the sticky dog sperm that covered somewhat most of his body.
His fingers curled through his hair and over his chest, then over his ass. One of his fingers trailed near his widened butthole to feel the last drops of Cal's cum slowly drip out of it.
Smiling, Mark took up a drop of the seed with his fingertip and raised it to his mouth. A second later his tounge lapped away the still warm cum.
While the water continued to wash away the last vestiges of the sex with his friend Cal, Mark's hands now trailed lower on his body.
Slowly opening his eyes, the young man started to examine his new dog sheath.
Everything looked just... right. It feeled like he was supposed to have a dog cock all his life. It was just natural.
Slowly stoking over the soaked fur on his sheath, Mark moanded slightly. The feelings of seyual exitement washed over him again as his new tool started to take control of his emotions once again.
Slightly pulling down on his sheath, Mark revealed the shiny red tip ov his new dog cock, which was more than ready to go for another round.
Mark started to slowly caress his furred balls with one hand while stroking hos sheath with increasing intensity.
Soon his glistening cock grew out more and more from his sheath, a tip of precum glistening on it's tip.
Suddenly Mark's heart skipped a beat as there was a knock on the bathroom's door.
"Hey, who's in there, I have to take a piss!", Mark's slightly younger brother Toby yelled.
Still stroking his straining dog cock and balls, Mark's view trailed to the bathrooms door. His smile turned to a predatory canine grin.
His new tool would see some more use after all...