Whitney Houston’s 19-year-old daughter got away with a crime that everybody gets away with in Vegas … she gambled underage … and it was all caught on tape.

Bobbi Kristina was facing off with a slot machine at the MGM Resort and Casino Saturday night … while hanging out with her 22-year-old boyfriend Nick Gordon.

It’s unclear if Bobbi actually won any money … but it’s highly unlikely she walked away with anything significant … because casinos usually require an I.D. before handing over large prizes … and ya gotta be 21 to gamble in Vegas.

In fact, people under the age of 21 are usually forbidden from hanging out ANYWHERE in the casino area … so it’s a bit surprising BK was able to pull up a chair and hang out with the one-armed bandit for as long as she did.

Bobbi Kristina was in town to attend the Billboard Music Awards on Sunday … where she accepted the Millennium Award on her mother’s behalf.

A rep for the Houston fam who had no comment.

Check out the video here:

Via “”