How do I fix this?

[ABC123]

I have a hdhp through my employer with a HSA.  Dh is on his employer's insurance with a PPO.  They just started offering a FSA this year.  He signed up for it, not realizing he wasn't allowed to since technically he could use mine even though he isn't on my plan.  We are nowhere near the limit of either account. Is there a way to fix this?  Or are we majorly screwed?  I appreciate any advice anyone might give.

[ABC123]

I tried googling this, and all I could find was that you aren't supposed to do it. Nothing about how to fix it or what the penalties might be.

[mozar]

You can just take the money out and close it no? I think you would get in trouble if you put it on your taxes and you would get a letter from the irs saying you can't do that.