Krayzie Bone -- Finally Puts A Ring On It (UPDATE)

5:15 PM PT -- Wedding mixup ... Krayzie didn't marry his baby mama Andrea after all -- he tells us he actually tied the knot with a different Andrea (he's got a type). They don't want to reveal her last name, but he says they've been together for 3 years.

KB says they did it at a courthouse because they didn't want to wait, but they are planning to have a big ceremony next year.

As for the mixup -- Krazyzie's camp got their Andreas twisted.

Krayzie Bone was at a Crossroads ... and chose the path to married life.

The Bone Thugs-N-Harmony rapper finally got hitched to his long-time girlfriend Andrea on Wednesday in a private ceremony at an L.A. courthouse ... after 13 years of dating.

The couple has 3 kids -- Nathan, Malaysia and Anthony. Krayzie has 2 other daughters from his 1st marriage.

Back in July, Bone Thugs announced they'd be reuniting for one last album and a final world tour ... set to kickoff in December.