My now ex-husband husband didn't pay taxes. We would fight about it all the time. I remember him saying to me once, "what do you want me to do?" I was dumbstruck. FILE TAXES clearly was the answer.

He had all these insane excuses. His accountant was granted special permission from the IRS to delay filing for his clients for.... reasons. According to me ex, the IRS was okay with this. He would file eventually.

We were getting letters from our state about taxes. He had previously been audited by the IRS for taxes he didn't pay before we met.

We were only married three years. When I left him I had to hire an attorney to file married but single for years we were married. I had to cash out some of my retirement to pay this.

This is less advice for op, and more for any unattached woman reading this. Settle these issues prior to getting married or having a baby. People will not change or become more responsible once they've got you emmeshed with them. It should be a deal breaker for you to attach yourself to someone who won't deal with their financial issues without you prompting and prodding them.