VIDEO : Michelle Obama Signed Copies Of New Book At A Costco Ahead Of Ellen Appearance

Ellen DeGeneres took Michelle Obama to Costco recently. In a preview of Obama's appearance on DeGeneres' eponymous talk show on Thursday, the host took to the keyboard while the former first lady signed copies of her new book, "Becoming." DeGeneres serenades the crowd while making humorous digs at Obama for mentioning Oprah Winfrey more than her in her memoir. The pair have been friends for years, and it's not the first time they've wreaked havoc in a store. "She mentions Oprah [Winfrey] several times and me only once. In 2012, the pair had a push-up contest on DeGeneres' eponymous talk show, which Michelle won.