The thing with CW is you can display the cards very fairly at almost finger tips before you get started.
Just doing that naturally and casually
should stop anyone from questioning anything.
Are the people who want to inspect your props mainly friends and family? you will often find these people will want to "bust" you more than strangers!!
Also you may wish to seriously consider if you are doing anything, even something very subtle to tip the fact the cards are unusual, From saying "here i have two regualr cards", Handling the cards too delicately too just seeming very nervous!
Also how many times have you performed this if you have done it twice and one person asked you may have been unlucky. However if its nine times out of ten have you have a problem
