Another day, another new chick to bang!

Little lothario Justin Bieber brought a new bang buddy out partying at Hooray Henry's in West Hollywood on Monday night. We'd try to learn her name but it seems like it may not be worth the effort since the Biebs basically has a revolving door of ladies willing to bone him -- we have a feeling she will be dunzo in no time.

For the outing, the Biebs wore an odd ensemble, consisting of a layered long white shirts, an almost cropped looking denim jacket, tan pants and white kicks. The 21-year-old covered up his platinum locks with a beanie.

The mystery girl, who looks like a brunette Hailey Baldwin, was outfitted in ripped jeans a cropped turtle neck and a leather jacket.

We wonder if JB will get confused and accidentally call her Hailey?! We doubt this chick will even care!