Protective Mother in Law logic
The mother-in-law, comes home and finds her son-in-law furious and packing his suitcase.
"What happened ?"
"What happened? I'll tell you what happened! I sent an email to my wife saying that I was coming home from my trip today. I got home and guess what I found? My wife, yes my Rachel, with a naked guy in our marital bed! This is the end of our marriage, I will leave forever!"
"Calm down!" says mother-in-law. "There is something odd about this story. Rachel would never do such a thing! Wait a minute while I check what happened."
Moments later, mother-in-law comes back with a big smile. "You see, I said there must be a simple explanation ...
Rachel didn't receive your Email."