My fiancé and I, Are very much in love with each other, I have a lot of insecurities for some reason, But we have managed to pull threw them.
She has been loyal and faithful to me, From what I can recall on.

About 4 months after first dating, She received a letter from her ex boyfriend,
Which to her knowledge she wants nothing to do with, So we threw away the letter in the trash.

About a year later which is present, We are getting married soon, Don't know when but where planning, Were also having a baby she is 14 weeks as of now.

OK now.. today she received another letter from this guy, Now I have just snapped
Am I wrong for snapping? I know its not her fault but this guy is basically disrespecting me,
And I think she should tell him to back off, she has a real guy now.

But she says why even reply to him at all? She doesn't want to give him the satisfaction
I just am over-whelmed by all of this, I feel like I want to kick this guys a## is this wrong?
Am I crazy to feel like that? I mean how would you feel.

This guy obviously is either obsessed and can't get over losing her, or is just a wierdo
What should I do about this ?

I need some good advice on this, don't just reply to get points!

Yes you are wrong for 'snapping'. And you are not right in wanting to fight. You have her so you want to screw up and lose her? So the guy is a weirdo: she couldn't fix him; do you think you can? You want to see her feeling sorry for him? What if some old girl friend of yours wrote you and started polishing you up? Don't you think your fiancé would look small belittling her? This is a good opportunity for you to show some maturity; you going to need it being a daddy and all.

She's made her choice and that's YOU , why would you punish her for something that's out of her control??