Eventually, he might come to accept it in a grudging way. If Izuku is wearing the clothes for a good reason, like in a team - up situation where it's part of a strategy, Bakugou might tolerate it. But he'll still probably make some snarky comments about how Izuku better not ruin his clothes.
It could be part of a 'truth or dare' type of situation within their group of friends. Izuku is dared to wear Bakugou's clothes for a whole day. As he does so, he starts to understand Bakugou's fashion choices better and also how others perceive Bakugou based on his appearance. It might also make Bakugou a bit more self - conscious about how his clothes represent him.
Bakugou might be initially shocked. He's used to Izuku calling him 'kacchan' for so long that it's become a normal part of their relationship. So, when Izuku stops, it could throw him off balance.
Some people might be very accepting. In more progressive communities, individuals are likely to view it as a form of self - expression and respect the boy's choice. They would see it as just another way for him to show his unique personality. However, in more conservative areas or among some traditional - minded people, there could be negative reactions. They might stare, make unkind comments, or even try to stop him from wearing girls' clothes because it goes against their perceived gender norms.
Another reaction could be confusion. Draco might not know how to feel. On one hand, he has his Slytherin pride and his clothes are part of that. But on the other hand, seeing Hermione in his clothes gives him a strange feeling in his stomach. He might end up being more curious about Hermione and her reasons for wearing his clothes.
A husband could be a bit worried if they are in a place where there are a lot of people with inappropriate behavior. He might be protective and want to make sure his wife is safe and not harassed. But overall, if he trusts his wife and respects her choice, he should be okay with it. He might also join in on the fun and enjoy the beach or pool day with her.
All Might would probably be very supportive. He's always been about the spirit of heroism, not gender. He'd encourage Izuku (as a girl) to keep training hard. Bakugo might initially be shocked and then try to act all tough, but deep down he might be a bit confused about his feelings towards her. Ochaco would be excited to have another girl around and might become even closer friends with Izuku.
Well, Iida would probably have a very proper reaction. He might give Bakugou a stern talk about treating Deku right and being respectful on the date. Mina would be super excited and would start gossiping about it right away. She'd be all over Deku, asking him what he was going to wear and things like that. And Kaminari would probably make some silly jokes about it, like saying Bakugou was finally 'going soft' for Deku.
I'm not sure if there is such a specific fanfic available. Fanfic topics can be quite diverse, but this one seems rather unethical in the context of the characters' relationships. You could try searching on major fanfic platforms like Archive of Our Own or FanFiction.net to see if it exists.
Sakura might be initially shocked and then start laughing uncontrollably. She would probably tease Naruto about it for a while. Sasuke, on the other hand, would likely just give a slightly raised eyebrow and then act as if it's not a big deal, but deep down he might be a bit amused. Kakashi would probably make a dry joke about it.
Hermione would probably be quite understanding. She might see it as an opportunity to promote equality and acceptance in the wizarding world. Ron, on the other hand, would likely be a bit more awkward at first, but would soon come around to support Harry once he realizes it's not a big deal.