Kim Kardashian and Kanye West headed to West Hollywood for a casual dinner out Tuesday evening, after returning to LA from Australia only hours before. But the usually uber-fashionable pair didn't bother to get dressed up -- Kim wore flip flops and workout attire, while Kanye looked a tad nicer in gray drop-crotch pants, a white tee and red high tops.

The hubby and wife dined at the Little Door -- a celeb favorite -- while they left daughter Nori at home with mom Kris and the nanny.

All we can say about this is ... Kim must be really tired to have gone anywhere other than the gym or nail salon looking that this. Her defenses are down, folks! The sexy bombshell is acting like a regular person!!!