You will have to file as either joint or married filing separately for this tax year because you haven't lived apart for the past 6 months (otherwise you would be eligible for head of household - a big benefit you'll be eligible for next year). A joint return would result in a lower total tax bill and since those are joint assets, so is the return. The exception is if you think you are at risk of liability for him cheating the IRS. Then you would definitely want to file separately.
Me 45 H 46 At bomb T 22 M 13 D14 S12
H fell in love 2/14 H moved out 11/14 H bought a house 8/15 Legal sep 9/15, final 12/15 - I filed No moves toward D
