After some pixiv tag research: Alfine (アルフィーネ) is the green-haired demon, pregnant with Beelzebub (ベルゼビュート), and Astaroth is carrying Asmodeus.
In the background, Belial (ベリアール) is orzing on the left, and Arioch (アリオク) is the armored one at right. post #482109 and post #482115 imply Belial is the father.
I had to look it up elsewhere, but silhouetted in the center is エルシーヴァ. Erushivua? That doesn't quite romanize to Lucifer. If someone can figure it out, please tag it.
Ah, thanks. I'd wondered what the heck was going on in this picture. I mean, you can make certain assumptions, but still, it's good to know the names (only knew Astaroth before).