Bobbi Kristina Oops, I Smashed Into My BF's Car

11/7/2012 12:20 AM PST

Bobbi Kristina
treated her boyfriend to a late-night bangin' session this week ... when she plowed her Camaro into his Camaro ... and TMZ has a photo of the wreckage.

Sources close to the couple tell TMZ ... it all went down inside the parking garage at the couple's apartment complex in Georgia on Monday night.

We're told Bobbi had followed Nick Gordon's car back to their place from another location ... and moments after he parked his car, she tried to back in to the next spot over ... and screwed up ... smashing the front of Nick's brand new car in the process.

Sources connected to the couple insist the crash was NOT alcohol related ... it was just a really expensive mistake.