It was an accusation of sexual assault that ultimately brought down Boris Johnson's government. When Conservative MP and whip Chris Pincher was accused of groping two men in a private members' club, the scandal was not so much the act itself but the accusations of a "cover up". In The Open Secret, a three part series from Sky News, political correspondent Liz Bates hears from others who have been scared to speak out about inappropriate behaviour and finds out why Westminster seems to struggle to deal with such claims.