Not much of note happened in this story.
Basically Persephone is super pregnant so Hades is treating her very delicately and not letting her over-extend herself or do anything that could put her in harms way so she has constant babysitters and isn't allowed to lift anything. She wants to share her love of the holidays with him, which includes going all out in decorations for Christmas, but he won't let her lift anything or stand on a ladder so she directs him and his minions on how to decorate. While I respect that he's being overly cautious being their first kid, and I get a lot of their sexual relationship is her being submissive to him and always doing what he wants, I found this super annoying when he doesn't ask or give her the choice, he just decides. Especially for something as personal as Christmas decorating, for someone who loves it so much and there's always a specific place things go, that would super annoy me.
But I did like him buying them an ornament to commemorate and giving her a care spa day like washing her hair and giving her massages since they're not able to have sex for fear of arousing her so much she'd go into premature labor (which is really funny, but could probs happen since I know some people use that to speed labor along). It's nice to check in with them and to see how truly happy they are at the very least, but yeah not much else happens. She does hint to her youngest sister, Eurydice, potentially forgiving Orpheus and knowing that there's a future book with them and Charon love triangle, or more likely polyamory knowing KR, it was good foreshadowing. I did appreciate that Persephone is still pissed at him for hurting her baby sister which same, so we'll see if he earns my forgiveness.