Need advice

I just came across an email of my husbands (yes, sometimes I look at his email becaue there have been trust issues) and it appears that he is trying to co sign a mortgage for his ex whom he shares a son with. This ex has never been anything but difficult and nasty since the day we started dating (5 years ago, married for 3.5 years). He's doing it completely behind my back knowing full well I would never agree, risking our livelihood (of which we are in vast debt as it is). In my opinion it's not okay to do that behind your spouses back for ANYONE let alone an ex who has caused huge issues. Thoughts? A: how do I get him to tell me without saying "hey I looked at your email" B: should I leave him? There are many other smaller issues, this just tops it.

You're correct, it's not the done thing to go behind your spouse's back in any circumstances. If you're having issues within your marriage then you need to look at counseling or trying to work it out yourselves using communication which allows you guys to have everything out in the open. If you achieve this, then you can make decisions as to whether you remain together or not. If you don't have trust in your marriage, then you basically don't have a marriage and your husband's latest actions indicate that he's not committed 100% to you guys together, regardless of his ex and his reasoning of co signing a mortgage with her. The fact that he's gone behind your back says it all.