I wore my sisters bra and underwear once. I don't know why, but I did, and I looked good
Just out of curiosity?
I'm not sure, maybe I wanted to play dress up. I tried the bra and it looked good...
Why not buy your own? Isn't it a bit strange to essentially steal your sisters undergarments?
What's wrong with it? It's just underwear, might as well wear my sisters, who would know?
Not saying it's necessarily wrong, but it seems sexual, and that's something you should explore without using your sisters clothing.