First of all, this is a very awkward and difficult situation. If it was an accidental sight, you may need to have a calm conversation with your wife about how she feels. And if it was inappropriate behavior from someone else, you should consider taking appropriate actions to protect your wife's feelings and rights, such as having a serious talk with the person involved or even seeking legal advice in extreme cases.
You can start by creating a calm and safe environment for her to talk. Assure her that she has nothing to be ashamed of. Maybe plan a special day out together, like going to her favorite place or having a nice dinner, to take her mind off this uncomfortable event.
If 'cock' is misused here and should be something else, it's very hard to make sense of. Maybe it was a typo and was supposed to be 'clock' or 'cook'. In that case, it could be about her seeing stories related to cooking or clocks.
This is a really tough one. I think you need to consider your friend's reaction too. If your friend seems apologetic and realizes it was a huge mistake, you might be able to move past it more easily. But if your friend doesn't seem to take it seriously, you may need to have a more serious conversation. You could also take some time apart to let the initial shock and embarrassment fade away a bit. In any case, always remember that your privacy is important and you have the right to feel violated by this accidental exposure.
No, it's not considered normal in a typical relationship. Looking at someone's private parts in this way is inappropriate behavior. There should be respect for personal privacy in a marriage.
This is a very embarrassing situation. First, you should try to stay calm. Immediately cover up and remove yourself from the situation as gracefully as possible. Then, you might want to reflect on how such an exposure occurred in the first place to prevent it from happening again.