My sister does something similar with a pack of porn cards she got given. Each playing card has a 80s picture of some naked lady or bloke. She slips a card into

My sister does something similar with a pack of porn cards she got given. Each playing card has a 80s picture of some naked lady or bloke. She slips a card into a wallet or bag then later (usually after a few drinks) she 'finds' the porn and shows everyone. She also reverse pick pockets them into random peoples pockets.