Kate Middleton had Prince William following her around like a lost puppy when she donned a 'sexy nurse outfit' following their brief split, according to a royal author.
Kate is said to have worn the risqué dress with fishnet tights to a "Freakin' Naughty-theme" fancy dress party which William invited her to.
At the time, in 2007, the university lovebirds had split - but William was reportedly desperate to rekindle their romance.
It's claimed he tried to persuade Kate to meet him at a pub to discuss their future, but Kate was in two minds.
Royal expert Katie Nicholl said: "They secretly met up at Clarence House and at a pub close to Highgrove, where William told her he wanted to get back together.
"Kate didn't want to rush anything. She had been badly hurt and told William she needed some time."
While the future-Duchess was mulling things over, he invited her to the party at his Army barracks in Dorset.
And given the theme, Kate, now 37, adhered to the 'naughty' dress code.
Nicholl, author of Kate: The Future Queen, claims Kate attended "dressed as a nurse - a rather sexy one in fishnet tights and a short dress".
And when William, now 37, saw her, he reportedly "pleaded" to give their relationship another chance.
It's claimed he "followed her around like a lost puppy" and the two "couldn't keep their hands off each other", according to fellow party-goers.
This is thought to be the night the couple - who met while studying at the University of St Andrews in Scotland - got back together.
Commenting on their brief time apart in their 2010 engagement interview, William said: "We did split up for a bit.
"We were both very young, it was at university and we were both finding ourselves and being different characters and stuff.
"It was very much trying to find our own way and we were growing up.
"It was just a bit of space. It worked out for the better."
Kate admitted she was upset about the break-up at the time, but in hindsight believes it was a good idea.
She said: "At the time I wasn't very happy about it but actually it made me a stronger person.
"You find out things about yourself that maybe you hadn't realised.
"I think you can get quite consumed by a relationship when you're younger.
"I really valued that time, for me as well, although I didn't think it at the time."
