Washington ? It’s decided: the Obamas have chosen a 6-month-old Portuguese water dog to be the first pet.

In what was one of the White House’s most tightly kept secrets, President Barack Obama’s daughters, 10-year-old Malia and 7-year-old Sasha, have settled on a black-and-white pup, a White House official speaking on the condition of anonymity told The Associated Press on Saturday night.

The dog, a gift from Sen. Ted Kennedy of Massachusetts who owns several Portuguese water dogs himself, will make his big debut Tuesday afternoon.

The Washington Post reported in its online editions Saturday night that Obama’s daughters chose the name Bo for the pup because first lady Michelle Obama’s father was nicknamed Diddley. The name for the dog was an apparent reference to the singer “Bo” Diddley.