BSL Glossary - Crowded Cottage
You must be joking - example
I was planning on going out one night when I realised that there was a programme coming on the TV that I really wanted to see. I asked my mother if she wouldn’t mind recording it for me so that when I got in from my night out I could watch it. She said "No problem". Off I went and when I eventually got back home, I said to her "Did you record it OK?" Mum said, "Oh! I forgot!" I said, "You must be joking!"