An excited Zoe, 16, is dressed and ready for her best friend’s long awaited birthday party.

She’s wearing a new dress (her dad thinks it is a little too tight), high heels and make-up. She’s so excited she can’t eat her dinner – but solemnly promises her mother, Bella, that at the party, she will not drink any alcohol, avoid the “bad girl groups” and call for a lift home by 11pm.