Our Roommate

My wife and i began renting our spare bedroom out to a girl who works with my wife. She is a about my wife's age but single and doesn't have many friends since she's new in town but she's nice and mostly keeps to herself. The other night, I noticed she was showering with the bathroom door slightly open. My wife was home so I told her what I'd seen. My wife dismissed it as "probably an accident" but it's happened a few more times since. And one time she was on the toilet and the door was wide open. She was blocked by door but I caught a glimpse of her in the mirror and I was able to hear her doing her business. The other issue is she sometimes walks around in really small shorts and tank top. I'm a faithful man but I'm being tested at every corner in my own home. I can't even go to the kitchen for a glass of water in the middle of the night without bumping into her wearing barely anything and sitting on the couch with half her ass showing.