I want to ask my wife to use a plate. She's leaving food out and its making a mess on the counter.
How do you know that it's hers?
I know it is and she needs to use it.
Make sure you do not come off as rude or controlling to her. It is not right to be controlling to your spouse.
She is just a slut, she needs to do this.
Wow insulting your wife for not using a plate is pretty extreme. If you want your wife to listen how about trying not insulting her and asking nicely instead of being controlling? That way she'll be more open to your request.