Tone and attitude: Your parents usually express a sense of distance and impolite tone to each other's parents, which may make them feel uncomfortable or disrespectful. My parents usually show their love and respect for their parents, which can also be used to distinguish them. Our parents usually express a close and friendly tone to each other's parents, and they can also express their respect and trust to each other.
Usage and occasion: Your parents usually use pronouns to express their parents in private or when communicating with outsiders, which is not suitable for use in front of their parents. My parents are usually pronouns used to express their parents in private or when communicating with them, and can also be used to distinguish them. Our parents are generally used to addressing their parents in private or when communicating with each other's parents. They can also be used to express intimacy and friendliness.
Geography and habits: Your parents, my parents and my parents' usage may also be influenced by geography and habits. Different regions or families may have different names and rules. Generally speaking, northerners are more accustomed to using the word za, while southerners are more accustomed to using your word or surname+parents. But this is not absolute, it depends on individuals and situations. To sum up, the differences between your parents, my parents and my parents are mainly in tone, usage and region. There is no definite standard and it needs to be judged according to the specific situation. If you want to address each other or your parents, please know their habits and preferences first, and then address them in an appropriate way to ensure smooth communication and respect.