Chris Brown Celebrates 37th Birthday With Private Las Vegas Party

While his baby mama drama keeps bubbling up online, Chris Brown was doing anything but stressing Tuesday night ... the singer celebrated his 37th birthday with an ultra-private Vegas bash surrounded by friends, family and a whole lotta pasta and steak.

Sources tell TMZ … The Guest House Las Vegas shut things down to the public around 10 PM so invited guests could roll in on the exclusive after-hours celebration, which lasted deep into the night.

We're told the evening featured a seated dinner, DJs spinning throughout the party and a birthday cake presentation for Breezy ... who's currently camped out in Sin City rehearsing for his upcoming tour with Usher and preparing for his 12th studio album -- titled "BROWN" -- scheduled for release on Friday.

The birthday cake matched the over-the-top Vegas vibe, too -- a towering three-tier chocolate creation decked out with gold accents, a glittery gold basketball topper and a message congratulating Chris on "making history."

And while things inside the party were reportedly smooth and celebratory, Chris’ personal life has been anything but chill lately.

As we reported … Chris and his baby mama, Diamond Brown, appeared to be taking subliminal shots at each other online this week following her paternity suit over their 4-year-old daughter, Lovely Symphani Brown.

Still, if the online tension was bothering him, Chris definitely didn’t show it at his birthday dinner. We’re told guests feasted on signature dishes including spicy rigatoni, steaks and Caesar salad while music kept the energy going all night.