My Mac is Taking Contact information from my phone. How can I stop this?

My wife has a special name on my phone - lets say "sweetie". So when she calls the phone says "sweetie".

This worked fine for years. At some point, however, the name "sweetie" polluted the address book in Mail - not only on my phone but on my Mac as well - so now if I email someone and cc my wife, that other person sees that I cc'd someone called "sweetie".

It's infuriating and embarrassing. Why is apple trying to think for me? Why is this information being sent to my mac? I should be able to call anyone anything I bloody want on my phone and not have it affect email.