The Don't Hold Your Breath hitmaker was about to go onstage at the Stand Up 2 Cancer live fundraising event in the U.S. in 2012 when she was told she needed a special T-shirt. Luckily, Cyrus was on hand to help.
She tells Britain's Evening Standard magazine, "My most embarrassing moment was backstage at the Stand Up 2 Cancer live event. I was about to go on when they told me I was meant to wear a customised charity T-shirt, which I hadn't done. Miley Cyrus ran over and lent me hers. Next time I saw her, she said 'Do you remember when me and my mum had to dress you?!' and I was like, 'I will never forget it!"