The "Ghosts 'n' Stuff" musician, 31, plastered Skrillex's phone number on his T-shirt while walking the star-studded red carpet. Skrillex's digits appeared above the text "U mad bro?"
Skrillex, 24, laughed it off via Twitter, writing: "Deadmau5 just wore my phone number on his f-ckin' shirt on TV. Gotta retire this phone."
Deadmau5 continued to tease his pal, who took home three awards that night (including Best Dance Recording, Best Electronic/Dance Album and Best Remixed Recording).
"Nice try with the call forwarding. One step ahead of you!" tweeted Deadmau5, whose celebrity fans include Snooki and Paris Hilton. "Congrats dude! Seriously, so rad!"
Though Deadmau5 walked away empty-handed, he still had a blast mingling with his favorite musicians. "No Grammys for me," he tweeted. "Oh well, I get to hang out with Dave Grohl, and that's pretty f-ckin' rad!"