Ashlee Simpson – Jiffy Pop In Real Life (PHOTO)

Ashlee Simpson is like a bag of buttered popcorn … ready to pop, and there’s only so much that slimming black dress can do to hide it.

Simpson is due any day with kid No. 2 -- her first with second husband Evan Ross -- and the couple did some last minute shopping in LA Thursday.

We gotta say ... Ashlee's wearing that massive bump like a champ, but it clearly runs in the family. Here's a pic of Jessica, also preggo with baby No. 2 from a couple years back. Huge resemblance.