It seems Pippa Middleton's friendship with Nico Jackson is more than just a fling.

It was a Middleton family outing as Pippa and her parents attended a high society wedding in rural Scotland - and there was even room for Nico, an investment banker, reports dailymail.co.uk.

Two of Pippa's oldest friends, Rowena Macrae and Julian Osborne, were tying the knot at the lavish ceremony in Perthshire.

The Duchess of Cambridge's 30-year-old sister was accompanied Nico as rumours of their own engagement remain rife.

Pippa, who came to the wedding wearing a cat dress by Suzannah and with a bag by Emmy London, met Rowena on a course at the prestigious 3,600 pounds-a-month cookery school The Grange, in Frome, Somerset. Pippa attended the culinary college on her gap-year before university and the two have remained close since.

Pippa has been with Nico, 36, for 18-months and their increasing number of cosy public appearances are fuelling suspicions that they could be ready to get married themselves.

Pippa met Nico, originally from Folkestone, Kent, who made his millions at Deutsche Bank, on a skiing trip.