Doing magic live on TV must be pretty nerve-racking - especially when you're having to count on Alesha Dixon!
Poor eight-year-old "witch" (Simon's words) Issy Simpson nearly had her performance de-railed during tonight's semi-final when she asked the judges to get involved in her act.
After Simon Cowell said that his favourite celebrity was Simon Cowell (no surprises there) and Amanda Holden had given her a time of 6.30pm and David Walliams had counted £2.01 in change from his pocket, it was just down to Alesha to read out what was written on her piece of paper.
"30,515," she said confidently, holding the paper aloft. What was actually written on it was 30,517 - which Issy swiftly corrected her on. Oops.
"Oh, 17!" exclaimed Alesha, citing how mesmerising she found Issy's performance as to why she was distracted.
Simon got in a cheeky quip to Amanda about using Botox before David Walliams joked that it wasn't good to give Alesha that kind of responsibility.