Humans are so frail. Break a bone or two, and they'll be out for weeks. A stab or a gunshot wound would be fatal if they're not so lucky. Or they're lucky enough to live their life and die from old age.
That's what happened with Chloe Morningstar. Per usual, her husband, who everyone thought was her son in the later years of their marriage, wasn't thrilled but there's literally nothing he could do. Although he's grateful that at least she spent the rest of her life with him.
But the pain of knowing that his wife was out of his reach made him restless. Everywhere he turns reminded him of the detective and it became unbearable. Despite the strong temptation which involved begging and pleading with God to return his beloved Chloe, Lucifer did not concede mainly because his dear wife promised she and the Almighty will have words.
The devil smiled at the mere thought of Chloe screaming her head off at God. He would have loved to see that.
Nonetheless, there was nothing left for him to do. Beatrice has her own family now and well-provided for. So, after all the goodbyes, he left everything behind and went back to his kingdom.
After all, misery does love company.
If you're gone
Maybe it's time to come home
There's an awful lot of breathing room
But I can hardly move
There's a little bit of something me in everything in you
-Matchbox 20