The pair had been at the centre of a media storm over the past week after being pictured locking lips in The Sun newspaper, despite Katya being married to fellow Strictly dancer Neil Jones and Seann being in a relationship with Norwich-born actress Rebecca Humphries.
Seann and Katya have both issued public apologies to their respective partners following their smooch.
"I'm so sorry about any offence or hurt I have caused with my actions".
She said: "Charles was the better dancer out of us two and there are some brilliant dancers in this competition and sadly I don't think I was one of them".
Seann added: "In light of the story in today's newspaper I would like to offer my honest apologies for my actions".
Rebecca, who accused Seann of being an "aggressive" boyfriend, told him in her public take-down: "Sorry I took the cat.' She was applauded for revealing how he had called her a 'psycho" for raising her suspicions about him and Katya. He made no mention of girlfriend Rebecca, amid reports the pair have since unfollowed each other on social media.
Comedian Walsh and Jones appeared on the BBC Two programme on Wednesday to address the kiss, which had resulted in Walsh being publicly dumped by his partner Rebecca Humphries, and which also prompted speculation around Jones's marriage with Strictly dancer Neil Jones. "Of COURSE. I'm so upset for you, I've been thinking about you all day", Marian responded.
Seann and Katya are set to continue dancing together on the show, despite Strictly Come Dancing bosses reportedly being "furious" about the situation.
It's very hard but I'm so glad you've been able to break free'.
There was a quick kiss on the cheek for Katya from Seann after they scored a rather generous 28 points from the judges, including an eight from Shirley who was adamant this week that she would be marking them on their dancing not their personal lives.
Following the circulation of the images, Humphries took to Twitter to share a powerful message about her relationship with Walsh.
She said she does not believe in the so-called Strictly curse, adding: "There are so many other reality shows that brings couples to either go apart, or get together - there's I'm A Celebrity, Big Brother".