You are clearly letting both of them control your life. Confront them both and if your wife won't believe you that shows serious weakness in your marriage. At that point its either counseling or divorce. And your mother in law should not be living with you.

Seriously? There has to be something she doesn't believe...see if stealing it back does anything...

use industrial adhesive on the toilet seat so the sitting down part is glued to the lid and refuse to fix it until they sit down to talk with you. you can also claim that you didn't do it if it causes a huge ordeal.

I really don't think that the issue here is that your mother in law steals. If your wife refuses to listen to you, you have bigger issues.

If you aren't willing to stand up to your wife then you might as well pack your stuff and leave now because this is not going to be a happy marriage.

Screw that. I would go get my money back.

You've got to stand up for yourself, regardless if your wife doesn't stick up for you. If you don't do something, they'll walk all over you and it'll be a miserable place to be in. Even if you feel that you're non-confrontational (like me), you pick the battles worth fighting and this is definitely one of them. Good luck.

Throw them both out. "Honey, if you're my wife and respect me, you'd believe me" if she still doesn't. Your marriage is already over. Leave her

Camera camera camera, and if there's still doubt, divorce divorce divorce. Life's too short man

go take it back