It took Xander a while to find something sparkly. He decided to wear the shirt that he and Alec had made together, but that didn't seem like enough, so, when Alec was distracted playing with Kiki, Xander snuck into Alec's room and dug through his clothes for something that would work. Thanks to their different physical activities, their body shapes were a little different with Xander being a bit more muscled in the shoulders and chest, but since Alec tended to like looser fits, Xander was still able to find a few things that might work. He snagged everything that looked possible and snuck back downstairs. He just happened to pass Dark as he headed downstairs with an armful of sparkly clothes. He looked Dark in the eye and wordlessly sidled sideways and down. Once he was in his room, then he sat down and went through his stolen goods, figuring out what would work together.
The next day, when he came upstairs, he had on a bulky black sweatshirt that hung down and concealed his entire upper body. It was not a particularly unusual thing for him to wear, so Alec didn't think anything of it. Alec, for his part, was wearing brown pants and a green shirt, which he admitted made him look a bit like a tree, but he liked the green shirt. He did complain that he couldn't find the belt he'd been looking for, but he'd settled for the leather one Xander had made for him.
When they arrived at school, Becky was wearing a jacket with a giant graphic with a cute kitten, but no sparkles in sight. She waved happily but then avoided the group, going to talk with other friends. Peter also looked normal in his usual "business casual" outfit that looked an awful lot like a school uniform in a school that did not use uniforms. His backpack was suspiciously full.