When a dog guards a woman from her husband, there are several possible causes for this behavior:

1. Defense of the territory:
Dogs often see household members as territory to be protected. If the dog feels threatened or uncomfortable by you, she may try to protect your wife.
2. Security and loyalty:
Dogs are very loyal creatures. If the dog feels that your wife needs protection, she may feel the need to guard her, especially if she feels uncomfortable or stressed.

3. Intuition:
Dogs can sense emotions and changes in the mood of humans. If the dog senses that you are in a tense or angry mood, she may feel the need to protect your female.
4. The relationship between the dog and your wife:
If the dog has developed a strong bond with your wife, she may feel that the wife is her "alpha" and see herself as her protector.
5. Unpleasant reactions in the past:
If there have been cases in the past where the dog had unpleasant experiences in the garden or was exposed to stressful events when you are around, she may develop defensive reactions.

6. Training or education:
If the dog has been trained to guard or protect people, this can be part of a learned behavior. Some dogs may have a natural tendency towards this behavior.
How to act:
Talk to your wife: It is important to understand your wife's feelings about this behavior.
Dealing with the situation pleasantly: Try to create a positive interaction with the dog so that she gets used to your presence.
Training: Consider training the dog to improve her communication and confidence in your presence.
Professional Counselor: If the behavior does not improve, you may want to consult a pet trainer or behaviorist.
In any case, it is important to be patient and create an environment where the dog will feel safe and calm.

And in the opposite situation when
Your dog is protecting you from your wife, there are several possible reasons for this behavior:

1. Defense of the territory:
Dogs may see their owner as a territory to be defended. In this case, the dog may feel the need to protect you from your wife if she detects a threat, even if it is not an actual threat.
2. Previous interaction:
If there have been cases in the past where the dog has experienced stressful or unpleasant experiences with your wife, she may develop a protective behavior towards you.
3. The relationship between the dog and its owner:
Dogs can develop strong bonds with one of the household members. If the dog feels a strong bond with you, she may feel she needs to protect you.

4. Emotional reactions:
If the dog detects tension or discomfort on your part when your wife is around, she may feel the need to protect you.
5. Training or education:
If the dog has been trained to be a guard dog or to protect humans, she may feel that she has to fulfill her role in this case as well.
How to act:
Talk to your wife: It is important to talk to your wife about the dog's behavior and see if she feels comfortable in this situation.
Positive attention: Try to create a positive interaction between your wife and the dog. For example, let them play together or give the dog treats when she is around your wife.
Training: Consider training the dog to strengthen her bond with your wife and reduce defensive behavior.
Professional Counselor: If the behavior persists, you should consider consulting with a trainer or pet behaviorist to understand the causes of the behavior and offer solutions.