S.coups:
The smile on his face would be huge. He wouldn't be able to stop smiling, probably because seeing you wearing his clothes makes him feel really happy. He'd tell you that you look great and that you should wear him clothes more often.
Mingyu & Jun:
He'd literally look as though he had hearts in his eyes. He'd have this huge smile/smirk thing going on. He would make it really obvious that he'd like that you wore his clothes. He'd make sure to tell you that you look great. He'd even leave some of his clothes around just so you could wear them. He'd would not be able to leave you alone.
The8:
He'd wouldn't even notice that you're wearing his clothes at first. He'd notice when you've already started talking or when he saw you walk by him. But when he does notice he'd ask if whatever you're wearing is his. When you said yes, he'd give you a warm smile telling you that he thought so and that you can wear his clothes whenever you want.
DK & Hoshi:
He'd love that you were wearing his clothes. But he would probably say something to you like, "if you can wear my clothes, can I wear yours too?" He'd end up coming out of the room wearing your clothes. Then he'd tell you that he looks great but not as great as you do, pulling out a cheesy line for you.
Wonwoo :
Just imagine wearing one of Wonwoo's bit sweaters and how they're so warm and still smell like him. But besides that, Wonwoo would tell you that you look super cute in clothes, though he'd be quite surprised first, he wouldn't complain.
Joshua:
He'd just have this smile on his face, not really knowing what to say, or how to express how he feels. He'd just tug lightly on the hem of his shirt that you're wearing, or place his hand on the hip of the sweats you're wearing to signify that he's sees what you're doing. He'd just smile at you and tell you that you look great.
Woozi:
He'd surprised when he sees you wearing his clothes so he'd laugh slightly. Wondering how you got them in the first place he'd ask you,but if you thought that he meant to give them back, he'd tell you that it's fine. He thinks that you look cute in it anyways, and he's get so flustered and have to cover his blushing cheeks from his cheesy words.
Seungkwan:
He'd be so excited to see you wear his clothes. Immediately having this bright smile end up on his face. As soon as he saw you he'd tell you how great you looked, not holding it back. He'd personally give you more of his clothes to wear, because he liked this so much.
Vernon:
He'd think that it's a very nice surprise seeing you in his clothing. It would just make him want to hug you but he's hold back trying to play it cool. He would ask you it's taken so long for you to wear his clothes though. But, expect that he'd surprise you with a hug at anytime.
Dino & Jeonghan:
He'd be so in awe. Even if you were just wearing one of his old shirts. He'd think that you look really pretty and wouldn't hesitate to tell you. He'd want to see you in more of his clothes afterwards.