if someone refers to the wife in the conversation, is that rude? [closed]

I'm not native speaker and my husband is native speaker one day after we argued I heard he was talking to his sister. I could hear her voice too, she said,

stop fighting you and the wife?

That sentence sounded really weird and I kinda felt like he talked behind me so she is kinda on his side and letting down on me while they were talking.

How should I supposed to take that sentence?

“The wife” / “the Mrs” can be just informal language, not necessarily rude. But tone of voice and other context are need to be taken into consideration.

With such a short phrase and little context, it may be that his sister is on ‘your side‘, scolding him for fighting with you. Or she might be speaking about a third party who is fighting against you and your husband. Or she might be unhappy with both of you, etc.

The answer to your question of whether “the wife” is rude is that the context you provided is insufficient for a yes/no answer.