if you feel uncomfortable or concerned about this situation, it's essential to address it in a respectful and sensitive manner. You could try having a private conversation with your sister, expressing your feelings and concerns. Remember that people have different styles and comfort levels with their clothing choices, and what may seem intentional to one person may not be the case.
Approaching the situation with open communication can help both of you understand each other's perspectives better and find a resolution if needed. Remember to be respectful of each other's boundaries and feelings during the conversation.