The secret behind AJ and Kai’s steamy tango? They reallyARE a couple now!

THEIR on-screen chemistry sparked speculation of a romance – and The Mail on Sunday can now confirm that Strictly contestant A.J. Odudu is dating her professional dance partner Kai Widdrington.

Insiders said the pair – who last night performed the Argentine Tango to the Stevie Nicks track Edge Of Seventeen – are an item.

However, they haven’t been struck by the infamous Curse of Strictly because both are single.

A source on the BBC One show said TV presenter Miss Odudu, 33, and her 26-year-old partner had made no effort to keep a secret of the fact that they had fallen for each other during intense, gruelling training sessions.

Mr Widdrington, who made his Strictly debut this year, is said to have been ‘floored’ by his partner, who is best known for co-hosting Channel 5’s spinoff Big Brother’s Bit On The Side.

In an audio clip on Strictly’s Instagram account recorded after a performance, Mr Widdrington, who once turned down a football career with Southampton, was heard whispering: ‘I love you, I love you so much.’

The source said: ‘Kai thinks A. J. is sexy. They have this lovely romance going on, things have definitely changed in the last week or so and they are inseparable, not just as dance partners but away from that, too.

‘It’s nice to see a Strictly romance where there is no curse, just two people who have fallen head over heels for each other. Those involved in the show have been watching this closely over the weeks and have thought this was always on the cards. It’s lovely.’

Miss Odudu admitted last week that they had ‘chemistry’, adding: ‘There is a lot of passion… a lot of romance, it’s thrilling.’

A Strictly spokesman declined to comment on their relationship.

The Argentine Tango they performed last night is considered one of the most romantic dances. Afterwards, Miss Odudu and Mr Widdrington – who are tipped as potential finalists – almost kissed in front of the live audience and the show’s millions of viewers. Host Tess Daly described the routine as ‘intense’, and head judge Shirley Ballas gave them a perfect ten after a standing ovation. ‘That was world championship level,’ she said.

Anton Du Beke awarded them a nine while Craig Revel-Horwood and Motsi Mabuse each gave them eight, taking their total to 35.

But Tilly Ramsay, 19 – who was called ‘a chubby little thing’ last week by LBC radio presenter Steve Allen – got 36 with her partner Nikita Kuzman for their foxtrot to One Direction’s hit Little Things. They received four nines, with Revel-Horwood describing it as ‘absolutely gorgeous’.