The Canadian singer performed White Christmas with the late crooner for a festive TV special filmed in his native Vancouver.
Michael tweeted: "What a dream come true to sing my favourite holiday song with Mr Bing Crosby. Check this one off my bucket list. #BubleXmas."
He also shared snaps of Christmases past with viewers and confessed on Twitter: "Showing my home Christmas photos... now you know I was always a dork!"
The Home For The Holidays show also featured duets with his "frickin' icon" Rod Stewart and Carly Rae Jepsen, who Michael described as "Amazing! Hot! Sexy!"
"Marry me @carlyraejepsen," he teased.