Justin Bieber -- Banging That Hooters Waitress Again

Justin Bieber can toot it, boot it, then toot it again -- TMZ has learned, he's back getting it on with a Vegas Hooters waitress he hooked up with last summer ... after dumping her for several other girls in between.

22-year-old Jordan Ozuna posted this photo on Instagram February 16th from inside the spaceship mansion Bieber's currently renting in Atlanta. We won't say how we know, but we know.

Bieber and Jordan first hooked up in Vegas last June -- Jordan worked as a Hooters waitress at the time. They were photographed going indoor skydiving together ... and even kissing ... but we haven't seen much of her since ... until now.

And if the bed photo isn't convincing, here's a picture of Ozuna playing around at a Dave & Buster's in Atlanta the day before Valentine's Day -- the same day Bieber was also photographed at the same location.

It's unclear what happened to Bieber's Miami chick Chantel Jeffries, but she's been replaced ... at least for now.