The Great Dane looked up at him and woofed, tail wagging, and then looked pointedly at the German Shepherd costume. Luke laughed. "Oh, right. Like I want to become a lady dog with you already showing a boner?" The Great Dane woofed and wagged his tail in agreement.
Well, it was just temporary. Luke flushed at the thought of having the boy mounting him, but his revulsion changed to curiosity. It wasn't the boy mounting him - it was a Great Dane mounting a German Shepherd. Seeing the dog proved that these costumes worked. And he could take it off afterwards, right? "Oh, all right. Let's see what this is like."
Luke picked up the German Shepherd costume and shook it out. It looked like the skin of a real animal on the outside, but when he pushed a foot into one of the legs the costume stretched. He managed to get both legs fully into the canine costume, looking like he was wearing furry leotards. The Great Dane was up and sniffing all around him,. tail wagging like crazy. Sliding his arms into the forelegs pulled the back and head into position. He found the zipper on the belly and pulled it up. The head was caught on his forehead, stretching the neck a little. As Luke closed the zipper all the way, he gasped and fell forward - balance suddenly shifted and he was disoriented and confused as the costume head slipped down over his face.
A wave of powerful odors hit him hard, and sounds were suddenly intense. He blinked, vision a little distorted and washed of color. The strangeness passed after a minute, and then he felt great. It was weird. He was a dog, knew he had been human, and still felt perfectly normal. A quick trot around the floor showed he moved on four legs easily. Luke woofed happily, very content. Part of him realized that his mind set had changed. He should be worried, or scared at least a little. But he just felt happy. And horny.
Luke remembered the male when he nosed her cunt and sent a shiver of pleasure and need through her. She knew she could resist, and a very small part of her thought it might be better not to go through with mating. The former boy had no such reservations. He was fully erect again, his large pink cock hanging under his belly as he pranced around Luke. The kid had never had sex before. Then again, neither had Luke, at least not real all-the-way sex. He felt slick and hot and needy.