Luke looked at the small clothes and shrugged. He gave Sampson a good scratch on the head. "Well what the hell, I came here for a costume didn't I? Since that kid took mine I guess it's only fair I take 'his'." Sampson barked but Luke couldn't tell if it was agreement or objection. He wondered briefly how much of the kid was still in there. Deciding he wanted some privacy for this, Luke went back into the changing room with the kids clothes. Sampson of course following his new master in. Luke shedded his original clothing, again, and took a glance over his current body. For a lanky 18 year old he wasn't bad. He had a boy next door charm with soft brown hair, bright green eyes. Average height a little thin but the tan and muscles of an active teen. Even down stairs he was doing ok at 6 inches. He didn't have to shave that often yet but he had also just begun growing some fine blond hairs on his chest and stomach which he was proud of. He was more than willing to give it all away though for a day as a carefree kid. Luke thought back to his first encounter and how the kid just strode right into the room like nothing mattered. Without a second thought he pulled the underwear up over his legs.
"Ugh wow what a TIGHT fit!" He exclaimed as his voice cracked a bit. But something felt strange. The tightness was easing up as his development went in reverse. His balls deflated and the hair around his dick vanished. It also shrank quite a bit. The loss of hormones affected his mind as well. Being an 18 year old Lukes mind was usually filled with girls sex and how to put the two together. But now girls were gross again and sex was a funny word. He giggled a bit before he caught himself. He couldn't believe this was working. The shorts and shoes came on next and his feet shrank many sizes instantly to fit right in. All across his body muscles shrank and hair vanished. Even for ten Danny had been a bit scrawny, he recalled.
"This is pretty cool!" Luke shouted in his new high pitched voice, he didn't mean to sound so giddy and childish but he couldn't help himself now. He felt full of energy and excitement. Wasn't there something the shop keeper said though? About the change being forever if he stayed too long or got too caught up in the mind? It was hard to think or remember his mind was buzzing. Oh well if anything went wrong he had his old clothes... Somewhere. He turned and they were gone. He looked over at Sampson just in time to watch him finish his change into... Himself.
"That's better." Said 'Luke'. "I didn't really wanna be a dog anyway, just needed a way to get you distracted and out of your clothes! Man this adult body is nice, I can finally think straight and I know what big words mean! Damn you sure think about girls a lot." The new Luke looked down just in time to watch the front of his pants tent. "Nice!"
"Hey that's not how it's supposed to be! You're gonna be my doggy!" Luke/Danny said lamely. The new Luke laughed and forced the small shirt over the old Lukes head. Immediately he found it harder to think. His face lost all signs of maturity and even gained back some baby fat. His hair lightened to blond and his eyes were a curious electric blue.
"Woah Danny that is no way to talk to your big brother Luke!" The teen scolded him. Luke quivered a bit from the deep voice. He felt powerless and weak before this larger person. "Now come on, we're going home little brother. I have some ideas." Luke didn't object as his old body took him out of the shop and to his new home.