Sensing he...she was following him, Derek turned around to find Stiles slightly shorter than usual. He glared at her - only halfway though because it was a pretty bad situation - and said, "Stiles. Either you need to put clothes on that will fit you or sit down." Motioning to the new body, Derek added, "Because this isn't going to work if you don't calm down." It wasn't a threat. ...Not really. It could be though, in a sense, but Derek didnt' mean it to come across that way.