This dance by professional dancers Vincent Simone and Flavia Cacace is just gorgeous and beautiful and haunting and it breaks my heart every time I watch it. Vincent and Flavia joined the show in 2006 and enjoyed mixed fortunes - he got all the way to the semi-finals with actress Louisa Lytton, while Flavia fared less well, exiting in week 3 when her partner Jimmy Tarbuck suffered a heart scare.
The following year, 2007, saw their fortunes reverse - Vincent, dancing with Stephanie Beacham, was eliminated first (and earned my never-ending devotion when she declared to Brucie and Tess that she was delighted to be put out of her misery); while Flavia got all the way to the final, finishing as runner-up with Matt DiAngelo.
As well as being dance partners since their teens, they were also boyfriend and girlfriend. That is until Strictly season 5. Flavia and Matt quickly became a tabloid dream, there were heaps of rumours about their chemistry not just being confined to the dancefloor, and I definitely remember papped pics of them sitting across from each other in a diner, almost holding hands. Pretty soon, it was clear the rumours were true, and Vincent did an interview where he confessed they'd split. Tess Daly, who never met a showmance she didn't like, consistently brought it up in every backstage interview she did with the pair - including directly after the final, when she commented that she was sure they'd keep seeing each other (nudge nudge, wink wink) when Vincent was standing just a few feet away.
They danced this exhibition waltz in the Week 9 results show, the split was common knowledge at that stage and you can see Vincent's heartbreak the whole way through this routine. (The fact that Flavia goes through the whole dance barely looking at him also speaks volumes).