Talk about an odd trio! Robert Pattinson hit up a Hollywood hotspot, The Larchmont, for dinner and drinks with old-school barflies Vince Vaughn and Joaquin Phoenix Friday night. Wonder what brought these three together?!

The group left a private party at the American bistro and headed home in a retro muscle car. Kristen Stewart was NOT along for the ride ...

Speaking of whom ... Kristen's 23rd birthday is this Tuesday. Will she and Rob spend it together?