On the day of the party, Nikki was stunning in her devil costume. And perfectly in character, she had designed some wicked torture for you. She gave you a very clear rule - you were not allowed to look at ANY girl's bra or panties. You knew the party would be full of sexy costumes, this could be bad! The penalty was 1 extra week in chastity every time she caught you peeking. But, you knew that if you had the opportunity, you would be unable to resist looking. You were too full of lust to possibly avoid it!
"Oh, by the way" Nikki teased, "If you peek at me or any of my friends, it'll cost you two weeks instead of one."