Justin Bieber -- Jet-Fueled Lies Just Don't Fly

Justin Bieber owns a brand new jet ... is what he wanted us to believe -- but we found it just ain't so. Hell, the G4 private jet he flaunted on Instagram wasn't even NEW!!

But at least Beiber didn't pull the same stunt with a Bugatti or a baller ass yacht -- and by that, we mean ... that's exactly what he did.