My mom is going through my stuff?

So my mom is divorcing my dad, and times have been very tough with trust. But today and yesterday i went to see my dad who is disabled, and has to live with his 80 year old mother. And when i came home today my mom locked everyone out of the house, and was vacuuming so she couldn't hear us. So i finally got in the back, and when i finally went up stars to sort out my room, the way i like it. I noticed that she went through my dresser. Now i can see cleaning **** off my floor, but not going into my PERSONAL dresser and belongings. Now normally i wouldn't care and even notice, but i hid my boxers for personal reasons before i went to see my dad and put them in a small chest. But of course she found them, washed them, and put them in the rightful place. But that was also my last pair so that's how i figured out. So i was wondering how i should confront her. And the honesty ship for her has sailed, and my nice boy attitude has also sailed.