Marvellous news from Sweden. Daniel Westling, a 35-year-old commoner, will soon bask in the pomp of his superb new title, Prince Daniel, duke of Västergötland. Even though I believe the last royal should be hung with the entrails of Boris Johnson, I can't help feeling envious. The fascinatingly named Swedish king Carl XVI Gustaf Folke Hubertus and Queen Silvia this week gave their permission for the former personal trainer to marry their daughter Crown Princess Victoria, 31.

The couple's eyes met across a room crowded with stairmasters and elliptical striders at Westling's invitation-only Stockholm health club in 2002. Today Swedes are so happy that they are, if not dancing in the streets, then forgetting that Saab is going belly up.

What's the best way to romp with a royal, you'll want to know. Become a personal trainer. Personal trainers are today's gamekeepers, bits of rough with pecs of steel and thighs like steel man (or, if you prefer, woman) traps. They're the modern-day equivalent of Lady Chatterley's Mellors or the ghillie immortalised by Billy Connolly in that film Mrs Brown. Personal trainers have been seducing celebrities for ages: think of how Madonna fell for Carlos Leon or how Priscilla Presley ran from the King of Graceland into the arms of karate instructor Mike Stone.

Here, of all the royals, only Princess Diana has followed their lead. Major James Hewitt galloped into her affections after becoming her riding instructor. And she never married him, of course.

In Scandinavia, by contrast, it's not uncommon for commoners to marry royal posh. Think of Mette-Marit Tjessem Høiby, regularly written up as a single mother, waitress and daughter of an unemployed alcoholic. In 2001, she became crown princess of Norway after marrying Crown Prince Haakon Magnus.

Crown Prince Frederick of Denmark once walked into a bar in Sydney and said to his future wife Mary Donaldson, "Hi, I'm Fred from Denmark." Now Mary from Hobart is called Kronprinsesse af Danmark and gets to spearhead royal visits to the Faroe Isles.

In Sweden, flirting over the royal stretch mat prior to solemnising your relationship with nuptial vows in the royal chapel is not unthinkable. Perhaps our royal family should become just as liberal. On the plus side, this would mean the gene pool would become more diverse. On the other hand, it would make them less compellingly dysfunctional than hitherto. And if that happened, what would be the point of their continued existence?