In my jurisdiction, this would amount to being separated but living under the same roof. Tricky, but the law here allows for this.
I found this when researching for another post recently. (These apply in Ontario, Canada)
"Q: How do I become legally separated?
A: If there is “no reasonable chance of reconciliation” between you and your spouse you are “legally separated”. You can be “legally separated” and continue to reside in the same residence. The test to determine if you are separated, includes, but is not limited to the following:
1. do you have sexual relations?
2. do you go out socially together?
3. does one spouse do household chores for the other?
4. do you and your spouse hold yourself out as separated to third parties? "
You would also have your lawyers create a separation agreement to formalize financial, support, and custody issues. Such an agreement is rather important to protect you from being liable for debts that your spouse might incur.
Your jurisdiction may be quite different. Contact a lawyer in your locale and get advice.