Would you want to wallop him for this too?

My husband bites his nails. Last weekend we’re having dinner in a family restaurant, and I notice him biting his nails and flicking them away. He was sitting in the aisle, and so that meant he was flicking them towards the other diners. The need to smack him one was very real!!! All I could think of was some poor person finding one of his fingernails on their plate.

What would you do? Would you say anything? What would you say/do? When would you say it?