Silly question but if u had a house guest...

If u had a house guest would u be comfortable them just going into your room without permission or mentioning they are going in just to use ur mirror... esp when there is a mirror in the guests room & the main bathroom....?

Regardless if the house guest is a family member or not? In my case it's my brother & keeps going into my & my hubby room to use the mirror... the en suite... to & sit & read... like come on! Has to be some boundaries!