I grew up in the south, I was taught to be nice and polite, and mind my manners. I say yes sir or no sir ( or ma'am depending on gender ).

I have never been impolite on purpose, its not who I am. Me and my SO say thankyou alot to each other, if I cook dinner he thanks me, if he cleans the snow off my car or brings me coffee at work I say thankyou. Its the way we are. I couldn't picture being impolite.