By Amber Goodhand - Breaking Celebrity News News Editor

Surprise! Kat Von D and DJ Deadmau5 are dating, and they're in love.

The lovebirds were spotted in West Hollywood on Monday holding hands, publicly proclaiming their relationship -- with Kat Von D in a slinky red dress and Deadmau5 more casual in a t-shirt and cap.

Canadian performer Deadmau5, real name Joel Zimmerman, posted a barrage of photos on Facebook of his new lady love on Sunday titled "a day with kats," and then took to his Twitter account to profess his love.