It could be that your brother obtained some compromising material related to porn and exploited it to blackmail you. Maybe he's trying to get something from you or control your actions.
It depends on the platform or device you're using. Usually, you can look for settings related to history or privacy and find the option to delete it there.
This is a very inappropriate situation. You should firmly and politely decline. Showing your private parts is not only inappropriate but may also be illegal in many places. It violates privacy and social norms.
You should approach the situation with sensitivity. Start by calming down. Depending on his age, use simple or more complex language to explain the privacy of the body. You can also use this as an opportunity to teach him about respecting personal boundaries and appropriate behavior.
If it was an accident, you should communicate clearly with her. Let her know that it made you uncomfortable (if it did) in a calm and respectful way. Try to avoid making a big scene if possible.
Telling your mother about being in 'penis chastity stories' is a really bad idea. Moms usually expect to have conversations about more positive, healthy and family - appropriate topics like your studies, career, or general well - being. This kind of topic is way too private and inappropriate for that relationship.
This is an extremely awkward situation. It could potentially cause a lot of discomfort and embarrassment between the two brothers. If it was an innocent accident, it's important to communicate openly about how it made each other feel and make sure it doesn't happen again. For example, in a family home, brothers should be more careful about personal space and knocking before entering private areas.