First, it's really strange behavior. You could gently talk to your wife about the potential hygiene issues. Maybe she doesn't realize that the dog's mouth can carry bacteria. For example, dogs may have licked dirty things before and then lick the stories which might contaminate them.
No, it's not normal. Stories are likely something to be read and cherished, not licked by a dog. There could be a misunderstanding in what she is actually doing.
No, it's not safe. A dog's mouth contains a lot of bacteria which can cause infections in humans. Even if the dog seems healthy, it can still carry harmful microorganisms.
It can be normal in some cases. Dogs often show affection by licking. But it's also important to consider your wife's comfort and any potential health risks. If your wife doesn't like it or is at risk of an allergic reaction, then it's not really acceptable behavior from the dog.
You should immediately stop the situation if it's happening at that moment. After that, educate your wife about the possible diseases that can be transmitted through such contact. It could be something like salmonella or other infections. Also, make sure the dog has regular vet check - ups to ensure it's healthy and clean.
One horror story could be a dog licking an open wound on a person and the dog having a disease that then gets transmitted to the person. For example, if the dog has rabies and licks a fresh cut, it can be extremely dangerous for the person. Rabies can cause serious neurological problems and can even be fatal if not treated immediately.
One consequence would be the destruction of the marriage. The husband would likely feel violated and may not be able to forgive such a transgression. Additionally, it could cause emotional trauma for the wife herself in the long run as she may come to regret her actions. It can also make her a target of unwanted attention from the stranger or others who hear about it, which could put her safety at risk.
A hiker was lost in the woods. He came across a small, seemingly friendly dog. The dog licked his hand. But soon after, the hiker started seeing strange apparitions. Every time he closed his eyes, he could feel the dog's wet lick on his hand and then see a figure of an old woman who seemed to be angry. The hiker later learned that the dog was rumored to be a spirit's companion in those woods and the lick was a mark of being haunted.