Dinner Party Suicide

I have a new idea for a play, which was semi-inspired by a real-life event. My play will involve four characters (two couples) enjoying a dinner party. During the party, some information comes to light that results in the wife of the host couple killing herself. I was struggling to come up with a reason why - my problem was that all the ideas I had ended up being about the husband doing something really bad (e.g. murderer, pervert, etc). If this was the case, then surely the wife's reaction would be anger and hatred towards him rather than deciding to kill herself? So then I was toying with the idea that she discovers that he was a Nazi and had actively killed hundreds in the holocaust, and she herself was a Jew, but this was actually a true story I read in the Metro, so I didn't want to steal it. With the help of my trusty Alex, I've now come to the conclusion that he could have been some sort of paeodphile murderer many years ago, and the wife knew about this and helped protect him. At the party some sort of information comes to light from the innocent party guests, which reawakens the wife's guilt and disguist in her husband and herself and - BANG!