A funny story

When I was a little girl I used to sing and dance when I was alone at home. One day, I thougt I was alone and I started singing, but believing I was a superstar, it was very ridiculous. While I was dancing I heard a noise... my parents and my grandparents were laughing at me! All of them were in the basement, so I didn't see them. Now, when I'm watching TV with them and there's a person dancing they say to me: Come on! Dance! I don't know why it's so hilarious for them... but it's so shameful for me...