i just learned how to say "my wife" in portuguese, it just made me chuckle a bit "a minha mulher" - literally "my woman" because "mulher" is woman...
in bulgarian the formal expression is "sapruga mi...
"Minha esposa" is more accurate for my wife. "Minha mulher" is used to say that you are in a relationship with a woman, which can be girlfriend, fiance or wife.