Sarah Ferguson's sweet birthday tribute to ex-husband Prince Andrew

It's been more than 20 years since their famous split, but Sarah "Fergie" Ferguson never misses former husband Prince Andrew's birthday.

The Duchess of York shared a throwback pic to Instagram of the Duke on Feb 19, writing, "Happy birthday to the best man, father, friend.... Prince Andrew."

She added, cheekily, "Ooh the best looking."

The black-and-white snap showed a young Prince Andrew, now 58, looking regal and bright-eyed, dressed in a white-collared shirt and woolen V-neck sweater.

The famous friendly exes -- who share daughters Eugenie, 27, and Beatrice, 29 -- announced their engagement in March 1986, and were married in Westminster Abbey in July 1986.

By 1992, however, they decided to call time on their relationship and announced they had split amicably.

RELATED: Princess Eugenie is engaged

Since then, they've remained extremely close, at times sparking speculation of a romantic reunion.

Fergie's post (which she also shared to Twitter) has been liked more than 3,000 times. Naturally, royal fans were delighted with the public display of affection.

"It’s so good to see that you two have remained close," one person tweeted. "Really looking forward to HRH Princess Eugenie wedding."

While another added, "You two need to get back together."

It's been a month of celebrations for the Duke and Duchess, following daughter Princess Eugenie's engagement to Jack Brooksbank.

"We love Jack and I AM SO EXCITED to have a son, a brother and a best friend," Fergie wrote on Instagram at the time. "Eugenie is one of the finest people I know and so together it will be pure harmony."

Nothing like a bit of royal love, eh?