Its think fine to look if there on show, theres not a lot you can do if there just there infront of you. I used to work opposite a river island, once a week they used to hoover the window out (on all fours i might add so everythings a little looser) There was one paticular girl me and my mate used to go out of our way to stand at the door and "admire" She always used to give us a little smile when she stood back up and man did she wear some low cut tops. Ive just thought maybe she didnt realise we were watching her though and she was just being friendly