The tattoo artist turned reality star, 31, revealed that she and fiancé Deadmau5 (real name Joel Zimmerman) have split – but can't seem to agree on why.
"Man, I'm a fool," Von D Tweeted Wednesday morning.
She soon addressed what she was alluding when she announced the split on Twitter later that day.
"Cheating on your loved one is the most hurtful thing one could do. I hate to have to admit, that this relationship is indeed over," she wrote.
On Thursday, Zimmerman, 32, released his side of the story with a lengthy statement posted on his Facebook page that denied any wrongdoing.
"Kat and I split in November and I moved back home to Toronto. During this time, while we were broken up, I did have relations with another woman. Following that, Kat and I reconciled and I acknowledged being intimate with another person while we were estranged," he wrote.
"We did move past those issues and I proposed to Kat in mid-December. At the end of June, it was clear that the relationship was not working and we mutually ended the engagement."
He continues to address Von D's allegations of infidelity. "I was not, at any point, unfaithful to Kat during our time together."
"I don't wish to go tit for tat with these kinds of pronouncements and don't expect to comment further, but I do believe that those who have expressed concern deserve a more complete understanding of what transpired."
The couple, who became engaged last December, had planned to tie the knot with an "underwater-themed" ceremony on Aug. 10, the tattoo artist told PEOPLE in April.
"Being with Joel is the only thing that feels more natural than tattooing," she said at the time.
Von D was previously engaged to Sandra Bullock's ex-husband, Jesse James.
Cheating on your loved one is the most hurtful thing one could do. I hate to have to admit, that this relationship is indeed over.— Kat Von D (@thekatvond) June 26, 2013
With Reporting By JESSICA HERNDON
now back to music. ok?— deadmau5 (@deadmau5) June 27, 2013