It is a known fact that all daughters-in-law have problems with their mother-in-law.
Anyway... One day all the daughters-in-law all got together and decided to apologise to their mothers-in-law for everything they had supposedly done wrong.
A week later the daughters-in-law decided to take their families (including their mothers-in-law) on a picnic.
The mothers-in-law were all in one bus, which was the first to leave, On the way their bus had an accident and all the mothers-on-law died.

