Prince William & Kate Middleton -- Expecting a Second Royal Baby

Get ready for Royal Baby Fever all over again ... Prince William and Kate Middleton are expecting their second child.

Buckingham Palace Kate is once again suffering from hyperemesis gravidarum, as she was when she was pregnant with her Prince George, who was born last July. The condition is like morning sickness, only more severe.

The child will become fourth in line to the British throne ... behind Prince Charles, Prince William and Prince George ... and Prince Harry drops to fifth.

Some guys just can't catch a break.