Madonna's Christmas rules
Madonna performs on stage during her "Sticky and Sweet" tour at Morumbi stadium in Sao Paulo December 18, 2008.
Kate Hudson's 'sexual energy'
Kate Hudson finds monogamy difficult because she is "ruled" by her "sexual energy". The 29-year-old actress - who has a four-year-old son Ryder with ex-husband Chris Robinson - admits she struggles to understand the concept of staying faithful.