Britney Spears new son, Sean Preston, is to play the baby Jesus in his very own nativity scene this Christmas. The pop princess, and husband Kevin Federline, have transformed his bedroom into the nativity setting in celebration of his first festive holiday. The beautiful singer has splashed out on the lavish decorations - which include six waxwork models and several life-size toy donkeys and cattle.The 23-year-old singer is so excited about her first Christmas as a mum she has even bought a cherrywood style manger for her baby.A source close to the star is quoted by Britain's Daily Star newspaper as saying: "It cost an absolute fortune. But at least she didn't have to buy a baby Jesus - because Sean is playing the part"Meanwhile, Britney is set to become a mum again - after a psychic told her she will fall pregnant next year.The 'Toxic' singer told friends the medium predicted she would be expecting again with six months, according to America's In Touch Weekly magazine. The thrilled star allegedly seeks advice from a psychic whenever she wants to make plans for the future.