Boards
Carry on Caliphate
http://www.theguardian.com/world/2014/aug/22/egyptian-cleric-men-spy-women-shower
"If you were really honest and wanted to marry that woman, and you were able to hide and watch her in secret, and see the things that she wouldn't usually let you see before marrying her, then it is acceptable as long as your intentions are pure,"
Not sure to be honest.