Luxembourg lovebirds Guillaume and Stephanie so happy with just three months to go until their big day

Ever since announcing their engagement Prince Guillaume of Luxembourg and Countess Stephanie de Lannoy have been walking on air.

Snuggled up to one another at the Olympics Aquatic Centre, Guillaume, who is heir to Grand Duchy established in 1815, and his pretty Belgian fiancée seemed to be in a world of their own.

They did at one point break off from cuddling and laughing to wave a banner in support of their swimmers.

Capturing the moment for the lovebirds was the 30-year-old's sister Alexandra.

Stephanie, 28, already seems to be a favourite within the family.

When she showed off the dazzling emerald-cut diamond that sealed the engagement, her future parents-in-law Grand Duke Henri and his elegant Cuban-born wife Maria Theresa, looked almost as thrilled as the happy couple themselves.  

And why wouldn't they be? Fluent in French, German and Russian, Stephanie is also learning Luxembourgish to prepare for her role.

More importantly, she seems to be head over heels about their son   as good a guarantee as any that the youngsters will have as strong a union as their own.

The former university sweethearts, who met while studying in Geneva, seem to have the happiest of marriages. 

Since tying the knot on Valentine's Day in 1981, Henri, 57, and Maria Theresa, 56, have had five children, including Guillaume, and two grandchildren.