Performing a Dec. 30 show at Revel Resort's Concert Hall in Atlantic City, N.J., dad-to-be West, 35, couldn't contain his excitement and shared the couple's happy news with the audience of 5,000.
"Stop the music for a second. Can we make some noise for my baby mama?" a beaming West said during a break in the show, referring to his girlfriend in the audience. (Watch video above)
During the concert, West dedicated a song to his three months pregnant girlfriend, 32, and was overjoyed as he sang lyrics including "this is God's plan" and "we are having a family" to announce the pregnancy, a source at the concert tells Us Weekly.
Longtime family friends, Kardashian and West took their romance public in March 2012. "It's so nice to have a best friend in this game who understands everything you're going through," Kardashian -- who is still legally married to Kris Humphries -- gushed of West November issue of England's Tatler magazine. "I can't even think about being with anyone else than the man I'm with."