STRICTLY Come Dancing stars Seann Walsh and Katya Jones' chemistry was heating up for weeks in the lead up to their very public snog.

The comedian was caught passionately kissing the professional dancer in the street last week, but show insiders have revealed their flirtation has been going on since “day one”.

An insider on the BBC dance show told The Metro: "I saw it in its early stages. Chemistry in and out of rehearsals and on and off the dance floor."

Another person close to show told The Sun: “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.”

Last night Seann’s girlfriend Rebecca Humphries revealed she had dumped him after the snog scandal was revealed and claimed he called her a “psycho” when she suspected he was cheating with Katya.

She revealed he left her home alone on the night he was pictured drunkenly snogging the dancer – after denying anything was going on between them.

The actress took to Twitter to tell her side of the story days after The Sun On Sunday published shock pictures of Seann, 32, kissing Katya, 29, on a drunken night out in London.

Rebecca, 32, who has now moved out of the home they shared and taken the cat, confirmed she’s dumped Seann.

She went on to claim he left her at home on her birthday to go out for one innocent drink" with the dancer and “aggressively” called her a “psycho” when she voiced her suspicions.

The actress wrote: “These pictures were taken on October 3rd. It was my birthday.

“I was alone at home when Seann texted at 10pm saying the two of them were going for one innocent drink.

“We spoke and I told him, not for the first time, that his actions over the past three weeks had led me to believe something inappropriate was going on.

“He aggressively and repeatedly called me a psycho/ nuts/mental.

“As he had done countless times throughout our relationship when I’ve questioned his inappropriate , hurtful behaviour.”

Seann was living with 32- year-old Rebecca in Hammersmith, West London.

Katya’s husband, Strictly dancer Neil, on the other hand has tried to ignore the scandal by going back to work and even posted a naked snap of himself online yesterday.

Seann and Katya’s shared grovelling apologies online on Sunday evening.

Katya said in a statement: “I’m so sorry about any offence or hurt I have caused with my actions.

“I wasn’t thinking and it was a one off mistake after some drinks.

“I love my husband and we are very happy together, this is not a reflection on our relationship.”

Seann added: “In light of the story in today’s newspaper I would like to offer my sincere apologies for my actions.

“This is no excuse but it was a one-off drunken mistake which I am truly sorry for.”

Yesterday the pair pulled the plug on an appearance on Lorraine Kelly’s ITV breakfast show.

Pictures then emerged of both Seann and Katya leaving their homes looking grim-faced.

He yesterday returned to rehearsals with married Katya, 29, at the BBC1 show’s Elstree studio where TV judges believe he should be kicked off.