Said to be worth more than £30million each, by the laws of showbiz at least one of them should by now have succumbed to the traditional hazards of child stardom.
A source recently told The Sun newspaper of the romance: 'They've adored each other for years and people have often thought they were together - but it's only recently they finally became an item.
This is a pretty good site for APUSH review as it follows each time period and includes primary sources.
Beware of bias in every historical source, including textbooks, websites, and teachers.
Donnelly and Mc Partlin soon became the famous duo known today, who host Ant and Dec's Saturday Night Takeaway, an entertainment show in which they compete against each other and the audience can win prizes.
They also host ITV's reality TV show I'm a Celebrity... in which celebrities are placed in the jungle in Australia and have to compete to win the show. In April 2009, Donnelly and Mc Partlin achieved wide international exposure after interviewing Britain's Got Talent contestant Susan Boyle, whose audition would become the most-viewed You Tube video of 2009. Ant & Dec have their own production company Mitre Television where they produce their shows.
They added: "They're keen to start a family and want to get hitched next year.
The star, who won the award for Best Entertainment Performance with sidekick Ant Mc Partlin, couldn't take his eyes off girlfriend Ali Astall, who looked stunning in a printed dress.
Ashley Roberts is happy for ex Declan, who recently got engaged "I'm happy for him," added the 33-year-old, who was wearing a plunging black leather top, black trousers and jacket at the Grosvenor Park.
But that's not the case for the women who share their lives.
In fact, although both men are the devoted, marrying kind, their partners have been kept in the shadows and are rarely photographed with them. The double act - insured against each other's death for a rumoured £1million - have worked hard to keep their private lives just that.
Declan Joseph Oliver 'Dec' Donnelly, OBE (born 25 September 1975) is an English television presenter, producer and actor, best known as one half of the British acting and TV presenting duo Ant & Dec, with the other being Anthony Mc Partlin.
Donnelly came to prominence in the children's drama series Byker Grove and as one half of the pop music duo PJ & Duncan.