Sister in law move in do i need to change my ways?

My family was always very open about their bodies and I have been this way my whole life. My wife and her sister was brought up nearly the same way so what I am wondering is what is acceptable around the SIL who just move in with us . Do I have to put PJ’s on ever time I run to the bathroom? Is it ok to sit in our hot tube in my boxers late a night by my self and have a beer?What about in the morning when everybody is trying to get ready for work we only have one bathroom? Do I just have a conversation with her and ask her what is acceptable and what is not? The wife just laughs and tells me not to worry about it when I ask her so she no help.I like the way I live and would rather not change much any advise would be great.