Great story! I enjoyed reading about how you let your fantasy become reality. You made the right decision to hesitate and let your sister pants you. Hopefully not only she, but her bff got a good view, and you hesitated in pulling your trunks up.
Interesting times back then, eh? Do you know if other people saw the photo your mom took of you in your sister's dress? Moms seem to like embarrassing their sons. :oops:
How long of a look did you have of your sister's boobs?
I too have set up embarrassing situations for myself where family ...
Unfortunately there was not such a rule when I was in school. A little CFNM would have made life more interesting. ;)
There is something about that pamphlet the women don't want the boys to see. Nice that the nudity rule is there to force males to show proper respect for the women.