There are times that your "partner" in life slides from being your anchor and rock and becomes an antagonistic part of your world. I'm sure we've all seen it. The guy who calls his wife "fat" in public. The woman who picks on her husband's clothing choices incessantly. Somehow the person who is supposed to "have your back" is stabbing you in it instead.
So let's say your partner keeps calling your home "white trash" - a derogatory term for a poorly kept, run down location. Here are the steps I would take.
First, I'd keep in mind that he was probably trained in this perception by others. Maybe his parents hammered it home to him that people in homes like that were to be looked down on. So he has decades of training in this thought pattern and that is hard to break. We all have those childhood training messages that are so thoroughly driven that they're hard to even think about changing.
Next, to be fair, I'd look to see if there's a kernel of truth in what he's being triggered by. It's one thing to dismiss him as being completely insane
It's another to step back and say, OK, maybe there is something that we can work on. That way you can acknowledge that you see his concern, and together you can find a solution.
The key here is that healthy relationships rely on supportive communication. If one partner is using deliberately hurtful words, then that is not a good sign. Communication should be done in a way to reach positive forward growth, not hurting the other person. So - and I know this is challenging - see if there is a way to find a quiet time and then say something like this -
"I feel hurt when you use the term 'white trash'. Trash is something useless - it cannot even be recycled. If you mean you do not like to have a messy home appearance, could you say that instead? That way I know what the issue is. A mess can be organized. The word "trash" is a permanent, negative connotation which does not leave room for improvement."
I would bring it up each time he uses the phrase, and any time he uses another better phrase I'd be very happy about it. That way you use both negative and positive reinforcement.
In the long term they say that continually rewarding positive statements works better - but I do think it's also worth bringing up your feelings about the use of the negative phrase because it's a symptom of a larger issue.