Ty realized a good starting point would be using his wishing powers on Andrew's hairline. "C'mon in," he smiled as he wished, and he saw the other boy's hair rustle and lengthen to the point he'd clearly never go bald.
"Thanks," Andrew replied, and he reached up and ran his fingers through his hair confusedly, brushing a messy fringe out of his eyes. "I didn't think I needed a haircut again so soon," he murmured to himself as he followed Ty to his bedroom.
"So, why'd you come over?" he said as he opened his bedroom door and invited Andrew in.
Andrew's eyes widened as Ty said that. "Man, I know your foster parents are kinda jerks, but did they really make you forget-"
"Oh, of course!" Ty blushed. Trust him to forget something that big in front of his crush, when he'd taken the time out of his day to come over! "Thanks for coming over on my birthday, dude, it's really sweet of you!"
"No problem," Andrew replied, giggling a little. He ruffled his hair again, and noticed Ty blushing. "I swear my hair's gotten longer just now. Did... did you play a prank on me or something?" Frowning, he said firmly, "Ty, I know something's going on. Tell me."
All of a sudden, a flood of words clumsily fell out of Ty's mouth. "I... uh... Andy, I have a crush on you and I've never felt like I could tell you, and also, I woke up today and found out I have the power to wish for anything I want and it'll happen, and I used it to make your hair grow back!"
Andy looked at him in disbelief for a moment, like he couldn't decide which of those was more absurd. But then all of a sudden, he grinned slyly.
"...what?" Ty asked in a small voice. Still blushing, he demanded, "WHAT?!"