Kim Kardashian Celebrates Her Birthday ... And Everybody's Gotta Stick Out (VIDEO)

Kim Kardashian's 35th birthday bash was a sympathetic affair -- cause when you're 7 months pregnant the best gift is to be surrounded with a roomful of big-bellied women ... even if they're faking.

Kanye West rented out a movie theater Wednesday night for Kim's surprise party -- they watched "Steve Jobs" -- but more importantly ... he had all the guests wear fake baby bumps. The man knows the way to her heart.

Interestingly, Kylie Jenner decided the baby bump fit better over her butt. Based on this pic ... we ain't arguing.

Apparently, Kendall Jenner's invitation said "bra optional." Again ... who's complaining?