A woman pops round to her daughter's home only to find her son-in-law boiling angry and hurriedly packing his suitcase.

"What happened ?" she asks anxiously.

"What happened!!  I'll tell you what happened.  I sent an email to my wife telling her I was coming home today from my fishing trip. I get home and guess what I found?  Yes, your daughter, my Jean, with a naked guy in our marital bed! This is unforgiveable, the end of our marriage. I'm done. I'm leaving forever!"

"Calm down, calm down!" says his mother-in-law. "There is something very odd going on here. Jean would never do such a thing! There must be a simple explanation. I'll go speak to her immediately and find out what happened."

Moments later, the mother-in-law comes back with a big smile.

" I told you there must be a simple explanation ..... she didn't receive your E-mail!"