Jim Jones' Fiance Chrissy Gets ARRESTED FOR FIGHTING!!

Jim Jones' fiance Chrissy was ARRESTED over the weekend. She allegedly BEAT FIRE out of a girl . . . Here is how TMZ is reporting it:

Edgewater PD tells TMZ ... Lampkin was popped around 2:30 AM for aggravated assault and disorderly conduct ... we're told it was bad enough that the victim required hospitalization. She was bloodied and doctors had to stitch up the area above her eye.

This wasn't pure theatrics ... cameras were NOT rolling.

As for what started the fight ... we're told Chrissy got pissed that the alleged victim sat on the sofa she was sitting on and accidentally bumped into someone.