Kim and Kanye had just arrived Sunday at a warehouse in L.A. when he answered nature's call -- outside the building. Kim, rocking a new pink 'do, turned around and appeared to burst into laughter at Kanye's desperate need to pee.

Y'know this was an emergency, because the couple was fully aware of the paparazzi. Then again ... we haven't seen video, so it's possible 'Ye was just clowning for the cameras and not actually urinating. Either way, Kim was entertained by his antics.