The farmers and the mermaid

On a farm over in Italy along the coastline there was a farm where a mother and her 3 sons lived. The father had died years ago fighting in a war. Ever since the only income for this family was a lone dairy cow; which was milked daily. On one morning the mother went out to milk said cow only to find that it was laying dead in the pasture. She fell to her knees and began to cry uncontrollably. Shortly thereafter a mermaid arose from the ocean and tried to console her. She asked "Why are you crying my dear?" in which the mother replied "Our cow, our only source of income is dead. My family will surely starve!" the mermaid replied "I happen to know that you have three handsome sons. Mother I will make a deal with you. If your oldest son can fuck me more than 15 times I will bring your cow back to life." So the mother goes and fetches her eldest son who is 17 years old and explains the situation to him. he replies "Of course mother, I will do this for the sake of the family!" Well after 13 times the son drops dead from exhaustion. The mermaid feeling sympathetic tells the mother "If your middle son can fuck me more than 10 times I will bring your cow back to life." so the mother grabs the next eldest who is 15 and explains the situation. He agrees to fuck the mermaid, however dies after 8 times from exhaustion. Still feeling sympathetic the mermaid tells the mother that if her youngest son can fuck her more than 5 times she'll bring the cow back to life. The mother fetches her 12 year old and explains whats going on. At this point the 12 year old turns to the mermaid and replies "Nahhhh lets make it 20 times!!" as to which the mermaid is taken aback in disbelief. Shes questions his judgement but agrees to 20. After a few days the boy arises from the field from fucking her non stop, the mermaid herself almost dead with exhaustion rolls over and asks "How did you learn to fuck like that?!?!!?" as to which the boy replies "How do you think the cow died?"