My wife has a female coworker she's on good terms with, who often comes over to my house to crash meals.

The coworker is slightly overweight, has never had a boyfriend, and several people have introduced her to some, but nothing has worked out.
One time she came over to eat again, looking pitiful, and said she might be single for the rest of her life.
I joked, "No worries, if no one wants you, I’ll take a concubine and keep you."
My wife disdainfully said, "You don’t even look at your own situation."
Our one-bedroom apartment, where would three of us live?
The female coworker blushed and didn’t say anything, and the scene became awkward...
Yesterday, my wife inexplicably snapped at me. I asked her what was wrong out of curiosity.
She shouted, "I told you not to be so mouthy!" and then started hitting me.
Later, I found out that her coworker told my wife she had no objection to the previous concubinage thing, and she could also take out her savings to help us get a bigger house...