"Gaaahh!" Luke cried out as the Great Dane shot his load. The release should have helped, but now it felt like his whole back end was on fire! His butt was slick and hot feeling, and he was afraid there was blood. The dog finally relaxed enough to yank free of Luke's anus, making the teen shudder in relief as the tremendous pressure finally eased. He tried to throw the Great Dane off, but it just wrapped its forelegs around his chest tighter and started thrusting again. "Stop it, kid!" Luke felt the prod hit just below his abuses anus and braced himself for another assault. But then the dog drove hard and deep into a new place lower down, an opening with a very different reaction to the swollen dog cock.
Gasping, Luke's eyes went wide as intense sexual need and pleasure washed over him, muscles in his rump clamping around the engorged canine penis even before the now-familiar swelling of the dog's knot pushed in and got trapped within what had to be a canine cunt. This time Luke shuddered with pleasure, grunting as the Great Dane whined. The huge, heavy animal thrust, shoving Luke's face against the wall, and amazingly erupted with yet another jet of seed. This also felt very different, moving deeper inside Luke's body. Finally spent, the male lay over Luke's back and panted while Luke gasped and wheezed, sweating and trembling. The knot relaxed again, and the former boy pulled loose and sat down to lick his swollen pink shaft.
Luke reached back and felt his rump. Sticky semen was still dribbling from his anus, but the slick swollen lips of his new cunt were damp from his own fluids. The semen was inside him still. Did he have a womb? Was the Great Dane making him a mother? Luke did not want to have puppies! he was a boy, not a bitch! Sudden fear made him grab his own crotch, and he was relieved to find his human male parts where they had been before. At least mostly boy.
The dog looked at him and wagged his tail, tongue lolling. He looked very pleased with himself. Luke frowned. "Are you still the kid? Or just a horny Great Dane?" The dog got up and licked Luke on the mouth, which the boy found he did not mind so much. Then the animal picked up the shirt he had been wearing and dropped it in Luke's lap. "So you are still the kind in there?" The dog barked once and then nosed the shirt. "OK. I get it. But why did you fuck me like that? I think you could have made me pregnant!"
He got up and started to gather up his own clothes and the kid's. "You going to stay like that? I need to get home."