Bernard's mom is from Taiwan; he was raised that to break glass is bad luck and to reverse the bad luck you have to smack the glass breaker twice and they have to smack you back once. For instance, when he was growing up, if he broke a dish, his mom would slap him (lightly) on the hand and then he would have to smack her (lightly) on her hand.

Interesting...but er...what's the question?

Bernard's mom is from Taiwan; he was raised that to break glass is bad luck and to reverse the bad luck you have to smack the glass breaker twice and they have to smack you back once. For instance, when he was growing up, if he broke a dish, his mom would slap him (lightly) on the hand and then he would have to smack her (lightly) on her hand. Looking for source, history and usage of this tradition.