Tantalus (son of Thyestes)

In Greek mythology, Tantalus was a prince of the south of Argolis as son of King Thyestes. He was the brother of Pleisthenes, Pelopia and Aegisthus, and - according to Hyginus - also of Menelaus and Agamemnon. An alternative genealogy makes him the son of Broteas.
According to Hyginus, Tantalus and Pleisthenes were born to Thyestes and Aerope, wife of his brother Atreus. Boys's uncle/stepfather killed them both in revenge for his wife's and brother's betrayal.
According to Tzeztzes and Apollodorus Tantalus lived to adulthood and became the first husband of Clytemnestra. He was slain together with their newborn child by Agamemnon who married the Spartan princess after his death, against her will.