You should if itemize deductions are greater than the standard deductions.
Technically, you both are still married. Without a qualified child or person, IRS only allows you to file either married filing separately or married filing jointly. He should not file Single.
If he did file single, without him telling you, you can itemize if your total itemized deductions exceed your standard deduction which would maximize your refund. You would only concern if he filed married filing separately as you have to follow along with his itemized deduction option.
