I don't know about your relationship with them, but in my opinion, what you do is what you do. They don't have any direct influence over your existence, so let them think what they want to think, just keep being your awesome, friendly, helpful self and they'll see you for you, regardless of how things change. Just don't jump in with both feet, lol, make the outward changes more gradual. Plus, thanks to double standards, it's usually more OK for girls to wear boy clothes anyways.