Script (guión): Idioms, ‘behind someone's back’. If you do something behind someone's back, then you do it without telling them or without them knowing. My young cousin lives in a pub with his mum and dad and from a young age became addicted to peanuts. They used to sell peanuts at the bar and he would sneak into the bar when his mum and dad were away and take the peanuts, steal them and take them up to his room. This got quite bad and he carried on doing this behind their backs. It got to the point were it was two or three times a day, until one day his mother caught him, so she grabbed him, she grabbed his nuts, and she crushed his nuts in her hand, and said, ‘If you do that again, you'll have to go and live with your grandmother.’