My wife tells me that I was mean to her in her dream last night. What do I do and say to her about this? I apparently was so bad in her dream that she woke up very upset with me.
Tell her to dream that you apologize profusely and make it up to her.
Seriously, you may want to ask her if the dream is a sign of something in your relationship that you can address with her. Then just listen to whatever she comes up with. Don’t be defensive. Just listen.
When she is done speaking, if she came up with something, you might apologize and ask her how the two of you can heal it. If she came up with nothing, your offer to listen will be appreciated.