Kate Middleton begs younger sister Pippa: Don't upstage me

Kate Middleton begs her younger sister Pippa Middleton: Don't upstage me during Diamond Jubilee!Kate asks her sister to tow the line at the Queen’s festivities.Kate Middleton has told friends she fears party-loving Pippa Middleton will upstage her over the Jubilee Celebrations, but why is Kate Middleton William so nervous about what her younger sister will do?