Women, Would You Ever Dress Like This Around Your Brother?

I am 23 years old male and i share an apartment with my 19 year old sister. We go to the same university in california and in order to save money our parents put us up together. Growing up my sister and i were like best friends. We hung out with the same social circle, listened to the same music, had the same interests ect and now even we go to the same school. Well over the last year she has been living with me she has started wearing less and less clothes around the house. At first at home after she came home she’d just put on sweats or baggy pjs and lounge in that but over time she began wearing tight pants, then it was small shorts, then small tight shorts, and now she always wears shorts were half her butt hangs out, or shorts so tight she gets a “camel toe’ She has always been an athlete so she is in great shape so i understand wanting to show off but in front of me seems weird. She has even noticed me glance down at her butt or cleavage and said, “enjoying the view” so i do not know what to do. My question for the ladies is, is this normal for girls to dress like this at home? would you or have you ever dressed like that in front of your brother? and what would you say if you noticed your brother looking?