Fig: privately; out of sight

The international situation seems to be at a deadlock, but a lot of negotiating is still going on behind the scenes

La situazione internazionale sembra essere in stallo, ma le trattative continuano incessantemente dietro le quinte

The president, as well as owner of the company, officially stepped down leaving the position to his son, but, as a matter of fact, he remained active behind the scenes for years

Il presidente, nonché titolare dell'azienda, ufficialmente è andato in pensione lasciando il posto al figlio, ma in realtà ha continuato a lavorare dietro le quinte per anni

The theater was sold out, but the star, whom I met at the stage door, let me in so that I could watch the show in the wings

Il teatro era esaurito, ma la star, che avevo incontrato all'ingresso degli artisti, mi ha fatto entrare e così ho potuto guardare lo spettacolo dalle quinte

To have something "waiting in the wings" is a theatrical reference. The wings are the areas at each side of the stage that are hidden from the audience. The phrase refers to an actor/actress who is just out of sight, at the edge of the stage, ready to appear instantly