The comedian, 32, and pro star, 29, kissed outside a London pub on a night out, following weeks of flirting on and off the dancefloor.
Their steamy smooch will shock her dancer husband Neil — who works on the show — and Seann’s actress partner Rebecca Humphries.
A witness said: “They were snogging like a pair of teenagers and didn’t seem to care who might see them.”
Seann then pulled Katya in for a long, passionate smooch, repeating the kiss several times.
At one point Katya, dressed in ripped hotpants, tights and high-heeled boots, arched back to perform a sexy routine as the shaggy-haired stand-up star took photos.
Witnesses told how the pair left the Duke Of York in Marylebone, Central London, at around midnight on Wednesday.
Seann, 32, and Katya, 29, appear to be the latest pair to be hit by the show’s “curse” on relationships.
Last night 12million viewers saw the comedian perform a sexually charged paso doble with Katya — with his girlfriend of five years, Rebecca Humphries, believed to be cheering them on in the audience, unaware of their kiss.
The star pair have also danced a raunchy jive and tangoed to hit song SexyBack.
Katya’s hubby Neil has been a choreographer on the BBC show since 2014.
A insider said last night: “Seann and Katya hit it off from day one.
“They are always laughing and messing around, and are incredibly tactile with each other.
“It hasn’t gone unnoticed by cast and crew but no one expected this.
“It’s going to cause real ructions backstage not least because Katya and Neil have to work alongside each other week in, week out.
“It will be unbelievably awkward especially if Seann goes through to next week’s show.”
Mock The Week regular Seann and Russia-born Katya have been training for nine hours a day, five days a week.
She said of the regime: “From what I can see so far Seann is going to work really hard, but more than that he’s just so adorable.
“He’s never danced before but I’m sure the audience is going to fall in love with him. He’s already calling me Boss!”
Actress Rebecca has been at Seann’s side throughout the show.
Her social media pages are littered with loving references to her boyfriend.
And she has even gushed about Katya, who won the last series with actor Joe McFadden.
The Strictly curse
2004: Dancer Brendan Cole admits “something happened” with Natasha Kaplinsky after he split with his fiancee — the dance pro Camilla Dallerup.
2007: Flavia Cacace ends relationship with pro Vincent Simone for her EastEnders star partner Matt Di Angelo.
2009: Boxer Joe Calzaghe and dance partner Kristina Rihanoff start a romance. Joe splits from his girlfriend of five years.
2010: Flavia leaves Matt for dance celeb Jimi Mistry. They wed in 2013.
2013: Kristina dumps Joe for her dance partner, England rugby ace Ben Cohen, ending his marriage. Kristina and Ben are still together.
2014: Countdown star Rachel Riley divorces Jamie Gilbert after 15 months for her dance partner Pasha Kovalev, pictured with her.
2015: Corrie’s Georgia May Foote ends romance with co-star Sean Ward to date dance partner Giovanni Pernice.
2016: Louise Redknapp splits from ex-footballer Jamie. Reports link her to dance partner Kevin Clifton, who has a rocky patch with dancer wife Karen. They later separate. The Redknapps divorce.
On the night of the launch show last month Rebecca tweeted a meme of a cheerleader, captioning it: “Actual footage of me in the audience watching boy dance with fierce, kick-ass queen @Mrs_katjones. If anyone can turn Gene Simmons into Gene Kelly it’s this girl.”
A week later she posted the official show photo of the pair, writing: “I can’t bloody breathe. These two legends are working their asses off.
“Walsh has been doing moves on holiday, in coffee shops, around Westfield (shopping centre), at the pub, in his sleep.
“We have moved half our (very heavy) furniture to create an.. at home dance studio. I am living for it. Get behind them!”
Yesterday Seann hailed Rebecca’s support in an interview.
And he told how he cried reading a “good-luck” book that she had made and filled with messages from his comedy idols including Peter Kay, Jack Dee and Romesh Ranganathan.
Asked if he might propose soon, he said: “Ha! I’m not falling into that trap. I don’t want Rebecca to open the (paper) and think every time I stoop to pick up something I’m going to give her a ring.”
In the same interview, he said he refuses to cut off his locks for Strictly, but would let producers wax his chest. He added: “In fact, I want Katya to do it.”
Sultry Katya wed Neil in August 2013 and they have been an item for ten years.
This week she posted a “throwback” picture of them in Cuba celebrating their five-year anniversary.
This is her third year paired with a celebrity.
Two years ago she got ex-shadow chancellor Ed Balls dancing to chart smash Gangnam Style.
Neil has appeared on screen for the past two years but has yet to be partnered with a star.
Katya, a former World Latin champ, has even petitioned for him to be made a Strictly pro next year.
She described their relationship as “solid”.
In an interview the couple told how he acted as house husband while Katya trained.
She said: “Yeah, fill up the bath for me, talk me through everything. It’s nice to have someone supporting you when you come back home.”
In OK! magazine last month the couple were asked if they wanted kids.
Katya said: “It is in the near future but I don’t want to plan.”
Source: Read Full Article