The mouse might become very still and quiet, as if it's listening intently. It could be curious about the new sounds it's hearing.
The gym teacher might initially be in shock. He could try to reason with the students, explaining that blackmail is wrong. For example, he might say 'This isn't right, you kids should know better.'
Sakura may also use her medical ninjutsu in a creative way. For instance, she could try to numb the part of Obito's body that is restraining her by using her precise chakra control. Or she might use some kind of medical jutsu to create a distraction, like a bright flash of light or a small explosion of medical energy.
He might be extremely embarrassed and try to hide. For example, he could run away and find a place to change back into his normal clothes as soon as possible.
He could be extremely resistant at first. He might try to fight back physically or verbally, refusing to put on the dress and getting angry at those who are forcing him.
In some fanfiction scenarios, Sookie could be surprisingly calm. She has been through a lot in the 'True Blood' world. She might see this as just another challenge. She could start to plan her escape quietly while pretending to go along with Eric's actions, biding her time until she can get away safely.
Percy might initially be confused. He would probably wonder why Annabeth, who was once his friend or ally, is treating him this way. So he could try to talk to her to find out what's wrong.
She would probably be very angry. Hermione is known for her strong will and intelligence. Being restrained against her will would likely make her furious and she'd start shouting at Fleur, demanding an explanation.
The mum could feel a bit helpless at first. However, she would likely try to be positive and encourage the girl not to feel bad. She might share her own experiences if she had any similar situations in the past, or she could research online about possible causes and solutions while making sure the girl feels loved and not judged.
Bella could also be surprisingly calm. If she has developed a deep understanding of the vampire world and Jasper's character over time, she might believe that there is a reason behind his actions. She may wait patiently for him to explain himself while also observing her surroundings for any possible means of escape or self - defense.
He could try to reason with Sebastian. Kurt is intelligent and articulate. He might try to talk Sebastian out of whatever his plan is, appealing to his better nature or trying to make him see the consequences of his actions.