What's the story/myth of tantalus?

One of Tantalus’ crimes was that he stole ambrosia from the Mt Olympus, although he was invited as a guest to one of the rich dinners of the gods. Later on, he took ambrosia and nectar and took them to his friends trying to impress them. Tantalus also revealed some very important secrets that Zeus himself had confined in him, betraying the hospitality and trust of the Gods. He was present in some conversations between the Gods and overheard some divine secrets, which he told to the mortals. Finally, Tantalus stole the favorite pet of Zeus, his golden dog. It is not absolutely certain that Tantalus himself did it, but he hid the dog for a known thief, Pandareus and then he refused to return it. Tantalus and the dinner to Gods punishment of tantalusAlthough all the above mentioned crimes were pretty insulting to the Gods, showing that Tantalus was on the wrong track, the Gods did not punish him at first, thinking that he would understand from his mistakes. Unfortunately, Tantalus did not correct himself but committed even worse crimes against them. Tantalus invited all the Gods of the Olympus to a feast and dinner. But either because he wanted to test their genius or because he did not have enough food, he decided to do one of the most disgusting acts in Greek mythology. He killed his son Pelops, cooked him roasting the pieces of his body and served him to the Gods. However, the Gods understood what was going on and refused to eat. The only one who decided to eat the food provided by Tantalus was Demeter, who ate the shoulder of Pelops. According to the myth, Zeus decided to restore Pelops’ life, and Demeter gave him an arm made of ivory, to replace the shoulder she had eaten during the dinner. This act could not go unpunished and the Gods punished Tantalus: Zeus killed him crushing him on a mountain and destroyed everything he had created, including his kingdom. But that was not the end… Zeus brought Tantalus to the Tartarus and put him into a lake with a fruit tree above him. Tantalus was doomed to suffer from hunger and thirst eternally, since he could not reach the fruit or the water. Although he was close to the fruits and the water, whenever he tried to take a piece of fruit or drink a little water, the tree and the water would move away from him, so that he could not reach them. The punishment of Tantalus was actually the eternal frustration that he could not satisfy his needs.