Why would someone make up these lies?

[E]

Guy answering: "Fiance dated right before your wedding" that makes him your husband now? She is jealous. If she can't have him she doesn't want you to have him either. Of course he didn't bring her up. Who would admit to dating a nut job like that. And looking back, would that have been what you wanted to hear at that time in your relationship. The fact he showed you the emails and you can see how unstable she is should be good enough. For the sake of your marriage you should file that info in the closed file. You two should move forward. Not everyone has a pristine past and life is not as neat and tidy as we wish. Don't color your relationship through suspicious eyes. At this point take him at his word. Is it possible he can cheat? Sure but if you are a good match and compatible he would be stupid to throw away a good thing like you. Do your best to put it in the past and build a trusting life together.