Never heard of that before ... IRS HOH rules are clear :
Considered unmarried
The IRS also requires all taxpayers who file as head of household to be "considered unmarried" as of the last day of the tax year. To be considered unmarried means:
You file a separate return
You paid more than half of the cost of keeping up your home for the tax year
You spouse did not live in the home during the last 6 months of the tax year
Your home was the main home for the qualifying person for at least 6 months of the tax year
You must be able to claim the child as a dependent
