Well, Maggien you may have answered your own question.. your husband!

When I live in the maritimes, a part of Canada with a unique accent, I once called home and caught myself saying words the same way they say them. For instance. In Vancouver we call say "car" "caaar" sort of extending the "a" sound. In the maritimes they say "Car" sort of like "Kerr" it's just human nature! As a Canadian back home I sometimes like to speak Mandarin with Chinese people in my neighbourhood (I live in a place with many mainland businesses, like restaurants and such) and they always know right away I lived in beijing cause I add the "rrr" on the end of words!

I think many people pick up accents from speech. I pick up accents when I talk to some people because I always been around them., a mid western Canadian or a bit of Scottish. Funny tho, one of my Scottish friends that I grew up with, I could never understand a word his dad said except ''teddybear'' I can imitate many accents, except from de islans mon.

My wife still has her Chinese accent

Could be worse

You could pick up a Kiwi accent

I speak Mandarin with a Japanese accent and I am not Japanese and I am not joking either -- perhaps because I learned very standard and rather fluent Japanese way before I even though about coming to China.  Very often and without knowing it I will slip Japanese words into the Chinese that I am able to speak and this results in everyone just staring.