Kim Kardashian is there to support her man and her BFF!

On Friday night, the reality star headed to Connecticut's Mohegan Sun to take in fiance Kanye West's concert and to celebrate close pal Jonathan Cheban's big 40th birthday.

After having a celebratory lunch at Cipriani in SoHo on Friday afternoon, Kardashian and Cheban traveled together to Mohegan Sun, a source told us. The "happy"-looking friends then hit up the concert, sitting together and waving to fans, added the source.