Electronic dance music superstar Deadmau5's underwater wedding plans have sunk - his fiancee Kat Von D has called off their engagement. The celebrity tattoo artist has accused the DJ, real name Joel Zimmerman, of cheating on her in a revealing tweet posted on Wednesday (26Jun13). She writes, "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... Onwards and upwards." The couple briefly broke up in November (12), before Deadmau5 popped the question the following month. The two were planning to tie the knot on 10 August (13) in an "underwater-themed" ceremony in Los Angeles. Von D was previously engaged to Sandra Bullock's cheating ex-husband Jesse James, but ended the relationship in 2011, six months after he proposed.