Undercover Brother Eddie Griffin Gets Married

Griffin and his fiancee Nia Rivers rolled into the Vegas Weddings chapel on Thursday afternoon -- where they took the plunge in front of 4 guests.

We're told the couple was in a "playful mood" -- and appeared to be very much in love.

Sources say the Griffins splurged on the Cherish Package -- which includes limo transportation, a bouquet for the bride, a boutonniere for the groom and 9 photos.