There was once a farming family which lived off their only cow. One day, the mother woke up to find that the cow had mysteriously died. Obviously distraught, she committed suicide, thinking that life was not worth living. A few hours later, the father wakes up and finds his wife and cow dead. He also commits suicide.
The eldest son wakes up and sees that his parents are dead. But while he was trying to take his life in the lake, up popped a mermaid who said, "If you have *** with me five times in a row, I will make everything alright."
The son tries desperately, but only manages three times and commits suicide. The second eldest son wakes to find that his brother and parents are dead.
Again the mermaid intervenes, "If you have *** with me ten times, I will make everything alright!" said the mermaid. The son tries, huffs and puffs but dies from exhaustion after only seven tries.
Finally, the youngest son wakes up, sees everyone dead, and attempts to commit suicide. The mermaid says, "If you have *** with me 15 times, I'll make everything alright!"
To which the boy replies, "Fifteen times?! You'll end up like the cow did after I finish with you!"