The Canadian DJ and the tattoo artist - who rose to fame on TV show `L.A. Ink` - have ended their relationship after just two months and officially announced their separation on 10.11.12.
Kat took to Twitter to vent her feelings, posting a series of tweets saying: "Man, I sure was wrong. But at least he made it a no-brainer to break that off. #lessonlearned. / Now, we can get all of the `I told you so`s` outta the way ... And move on. (sic)"
She added: "Clarification: Deadmau5 and I are no longer together."
Deadmau5 is assuming full responsibility for the split and posted a series of glum musings on his Facebook page.
He wrote: "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 wan`t to dwell on it right now. ill figure it out. no hard feelings. (sic)
He added: "it happened too fast, i lost my balance and fell into a familiar dark place that im having difficulty with. she deserves someone stronger... ... and thats it for the personal stuff... on with our regularly scheduled deadmau5 crap. (sic)"
Kat - who was previously engaged to Sandra Bullock`s ex-husband, Jesse James - and the music producer were very open about their budding romance when they were first pictured out together in September.
The ink-mad beauty - whose real name is Katherine von Drachenberg - expressed her love for Deadmau5 by giving him a star tattoo underneath his eye which matches her own.