Spouse Buying House With Possible Divorce Looming (indiana)

Location: Indianapolis, IN

Well, this certainly wasn't on my bingo card for the week. My stepson (28) texted my wife on Monday saying he wanted to drive up for a visit (we're in Iowa) as he needs to clear his head and step away from some drama. Not much detail until he showed up last night.

Turns out he and his wife (28) of 4 years separated a few months ago, and she is now starting hormone therapy to transition as a binary male (?). Okay, that's unfortunate and sad news, but life happens. He explained that their marriage has been having troubles for nearly a year and his wife has been making a lot of inexplicable choices without consulting him. Buying a car, spending thousands on chemo for her 17 year old cat, and... here's the fun part... she just bought a house on her own and closes on Oct 30th. She no longer wants to live with him but wants to stay married (for his ongoing emotional support, so she claims).

He's been leaning toward seeking a divorce but struggling with the finality of such a choice. He still loves her but is failing to see any path forward as a couple.

As an outside observer, the alarm bells are going off in my head. Relationship issues aside, what are his legal and financial obligations for this home purchase and mortgage? He says he won't be on any of the paperwork and she says she'll take sole responsibility for the property. But a quick search brought up Indiana's unique "one-pot" rule for marital property.

Neither of them have any assets to speak of, some credit card debt, her car loan. Previously, they were sharing a house with a friend where my step-son still resides. She makes $50k/yr as an admin assistant, and he makes $36k/yr "under the table" in cash (that's another conversation we'll be having).

My question is this: If he's ultimately going to file for divorce, should he do so before the 30th when the house sale is supposed to close? How does that complicate matters?

Thanks in advance for any insights!