I Think My Co-Worker's Husband Is Retarded

My co-worker's husband is probably not retarded. I'm sure he is very intelligent and able, but every day, I endure her talking to him on the phone and it always ends up escalating into a small fight, with her usually being the instigator and scolder. I'm actually pretty astounded that she does this almost every day. We have a small office where sound travels easily. Why do people want their personal business out there? Especially in a professional setting where you are to maintain some semblance of respectability, bitching out your husband on the phone every day isn't a step in the right direction. Reminds me of my other co-worker back in CT...