so to give a bit more back ground, my SO is going through divorce proceedings (he was legally separated several years before we met) he filed all past tax returns, his "ex" has not. She's fighting the divorce, but has asked him about a previous return, threatening that if he doesn't give her the info, it will stop the divorce proceedings. I think it's BS and that she about to get in trouble for not filing her taxes. So since he would have to sign for a joint return, I don't think he can be responsible for anything she owes.

No court yet, it's just a threat from her side (at least how I see it). He filed and has since they separated. She didn't file, which is why I believe she's asking. I just hate the threats. It's not a hill to die on, he filed married, but separate. There wasn't really a need for the threat, especially since it's complete BS. Nightmare, yes, and I think it's just beginning.