Knock and see who it is.

You giggle, shaking your head at the thought. Instead, you knock on the door. "Yeah?" Your brother answers. "Are you going to be long?" You ask. "Sorry, sis! I'll be out in a second!" You wait a few minutes before hearing the shower shut off. The door opens and out comes your brother, James. "Sorry about that, J." He walks down the corridor. You blush, having seen him in just a towel.

You enter the bathroom and start to close the door, when a thought occurs to you. If you left the door cracked, would someone peak at you?