Britain's Prince Williams girlfriend, Kate Middleton, has painted her royal boyfriend in the nude.The arty brunette has reportedly outraged Queen Elizabeth II by giving William the cheeky portrait for his 24th birthday, which he celebrated yesterday (21.06.06).The picture features the happy couple in a naked embrace, with their modesty covered by a strip of red silk.A royal source was quoted in Britains Daily Star newspaper as saying: "Her Majesty hasn't seen the painting yet. But her advisors have described it to her and she is disgusted."One presumes Kate and William have got to know each other in the bedroom but for Kate to blatantly announce it in a raunchy painting goes beyond the bounds of decency in the queen's eyes."The monarch has apparently advised the young lovers - who met at St Andrews University where they both studied History Of Art - to take their relationship more seriously and warned William that, as the future King, he should be careful to protect his reputation.The prince has reportedly decided to go against his grandmother's pleas and plans to hang the painting on his bedroom wall.

Another source revealed: "It was art that united them in the beginning, so Kate thought it would be appropriate to commemorate their four-year relationship with this romantic painting."