Walsh and Jones have suffered an enormous backlash after pictures emerged of them locked in a passionate embrace following a night out at a London pub.
She publicly broke up with Walsh in the letter, saying that she was "not a victim" and accusing the comedian of reacting aggressively when she confronted him over the kiss.
He continued: "I'm not ideal, far from it".
Mr Walsh's long-term partner said in a statement that he had called her "psycho/nuts/mental" when she suspected something was going on.
The pair both released statements immediately apologizing to their respective partners, but this morning, Seann's now-ex girlfriend, Rebecca Humphries, has released her own statement, calling Seann out for gaslighting and manipulating her.
Walsh's estranged girlfriend, the actress Rebecca Humphries, subsequently took to Twitter to say she has not received apologies from Walsh or Jones and alleged that Walsh gaslighted her when she voiced her suspicions about his relationship with Jones.
Appearing on It Takes Two tonight, Seann said: "I think that, obviously I'm sorry for the hurt that I've caused".
Speaking to host Zoe Ball, he tried to claim their relationship "wasn't perfect", but was sorry for the way it ended.
Walsh said the kiss happened after they had had a couple of drinks. That doesn't mean I wanted it to end how it finally did.
I have a voice and will use it by saying this to any woman out there who deep down feels worthless and trapped with a man they love. "We were getting on well, we were having fun", he said.
'But the main thing for me, me and Neil are absolutely fine, and that's what matters to me the most right now.
Picture: Instagram Seann Walsh and Katya Jones.
"I wasn't thinking and it was a one-off mistake after some drinks".
"This is no excuse but it was a one-off drunken mistake which I am truly sorry for".
"I love my husband and we are very happy together, this is not a reflection on our relationship", she continued.
Despite the controversy, the pair are continuing in the BBC One dance competition.