Kim Kardashian -- My Butt is Back ... And It Wants Taco Bell!

Dammmmmmmmmmnn .... is pretty much all you can say about Kim Kardashian's ass-entuating outfit for a Sunday afternoon outing with Kanye West.

The couple hit up a theater in Calabasas for a movie date and on the way out Kim proudly displayed her trademark in cutoff jeans and a back-baring top -- then they hit up a Taco Bell drive-thru.

You can tell from the photo ... Kanye gives this rearview two thumbs up. Way up.

Not to be a buzzkill -- but rubbing your bare back on a movie theater seat? Risky business.