Wife stripped

One time my wife’s sister and husband(the asshole BIL) came over to my wife’s parents, where she lived at the time. Her brother was also there. My wife had just gotten out of the shower and came up to see them wrapped in a towel which I wasn’t fond of lol. They were just all talking for a while. Then as they are about to leave her brother yanks her towel off( he did things like this occasionally). She’s standing there completely naked basically right next to BIL and her sister. She froze for a second then ran off to another room. To say he got an eyeful is an understatement.