Do you call your wife your wife? [Details inside].

Or your husband your husband.
Yesterday I had a chat with one of my colleauges.
I already knew he had children.
He mentioned them and also he mentioned his girlfriend.
I hesitated to ask but I did anyway, if his girlfriend was the mother of his children.
He said that yes, she was, and he was actually married with her.
She was his girlfriend when they met some twenty odd years ago, and she still is now (even though she is, legally, his wife).
He told me that he just cannot get it out of his mouth, the words “This is my wife.”
I am not married myself, but when I think of how I would introduce my girlfriend, once we are, I must admit that it sounds a little ‘alien’ to say “This is my wife” instead of “This is my girlfriend”.
What say you?