My Parents Are Aliens

When Lucy calls Brian and Sophie "Mum and Dad", Mel gets angry and shows Lucy and Josh a box of things she kept to remind her of their real parents. However, a lipstick is missing from the box. Lucy realizes that it was she who had taken it and swapped it, so she must ask Josh for help. Meanwhile, after a string of Fs, Josh must resit his exams or be put back a year. To pay him back for helping with the lipstick, Lucy helps him revise, and discovers that he may be dyslexic.