The 37-year-old and Ben, 36, were together for 23 years before he ended their marriage in 2014.
Now Abby – who shares twin daughters Harriette and Isabelle with rugby hunk Ben – has claimed he DID cheat with Kristina, 37, after meeting her on Strictly Come Dancing two years ago.
Speaking to The Sun, Abby said: "My husband, who I was with for 23 years, unconditionally loved and was completely loyal to in every respect, has left me for a f*****g Russian dancer.
"The last two years have been the most traumatic thing to ever happen to me. He's done the dirty on me. I want people to know."
Last month Kristina confirmed her romance with Ben, but insisted nothing happened until after he'd split from Abby.
Now it's been claimed that Kristina is considering quitting Strictly after the huge backlash her relationship with Ben has received.
A source said: "Kristina is at the point of resigning. She has been saying that she can't take the criticism day in, day out. She doesn't want it and can't do it anymore."
In July scorned Abby took to Twitter to share a lengthy post about karma, adding: "@KRihanoff there you go my lovely… [sic]."
Ben and Kristina have yet to respond to Abby's latest comments.