Kat Von D and Deadmau5 ended their engagement. They confirmed their breakup on social media, though both have different reasons for what came between them.

"Man, I'm a fool," the former "L.A. Ink" star tweeted Wednesday. "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 added today.

So did DJ Deadmau5 cheat on his fiancé? According to ABC News, Deadmau5, whose real name is Joel Zimmerman, was quick to defend himself on his Facebook page.

"Kat and I split in November and I moved back home to Toronto," he explained. "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. 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. 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," he added.

The tattoo artist, 31, and DJ, 32, first started dating in September and then were engaged in December. They had been planning an August wedding, the couple told People magazine.

Kat Von D later tweeted: "Onwards and upwards."

Kat was once involved in a public engagement with Jesse James, and when a fan tweeted to her, "Don't take him back no matter what. Ur worth more than that," Kat replied, "never."

According to E! Online, Von D then posted a photo to Instagram of a heart tattooed on her palm with the caption, "Go out into the world with Love."

This is not the first time the couple has broken up. In November, Von D wrote to her Twitter fans: "Man...Can't say I didn't give it my best" and "Man, I sure was wrong. But at least he made it a no-brainer to break that off. #lessonlearned."

Deadmau5 also wrote at that time: "Going to spend a little while screwing my head back on. i guess im not cut out for relationships right now. and that's all i really want to dwell on it right now. ill figure it out. no hard feelings."

They later reconciled, and Von D was seen wearing a black diamond ring that winter.