In Greek mythology, Chrysippus of Elis (or Pisa) was the beautiful illegitimate son of Pelops by a nymph (Axioche or Danais), abducted by Laius and later murdered through the jealousy of Hippodamia and her sons Atreus and Thyestes. The double crime seeds curses on both the Labdacid and Atreid houses. Distinct from the Stoic philosopher and from minor homonyms (a son of Aegyptus, and others).
Adapted from Wikipedia, "Chrysippus of Elis" · CC BY-SA 4.0
I.Abduction by Laius
Pelops loved Chrysippus above his other children. The exiled Theban prince Laius, welcomed at Pisa as the boy's tutor, fell in love with him and carried him off toward or from the Nemean Games to Thebes—ancient authors treat the act as rape. Pelops warred to recover his son and, in many versions, cursed Laius to die by his own child's hand. Minority strands name Zeus or even Theseus as abductor, or have Chrysippus kill himself for shame.
Euripides' lost Chrysippus staged Laius' passion, the abduction, and Pelops' curse; South Italian vases of the fourth century BC popularize the chariot rape. Some reconstructions link Hera's anger and the Sphinx to Thebes' failure to punish Laius.
II.Murder by the brothers
Hellanicus, Thucydides, and Hyginus have Atreus and Thyestes kill Chrysippus out of jealousy—often at Hippodamia's urging, fearing Pelops would leave the kingdom to the bastard—and cast him into a well. A variant has Hippodamia herself stab the sleeping youth with Laius' sword to shift blame. Pelops holds her responsible; she kills herself or withdraws to Midea, and he exiles and curses the sons—the Atreid curse that later consumes Mycenae.
The atlas id chrysippus is this Pelopid youth, not Chrysippus of Soli the Stoic, nor the Danaid-wedding son of Aegyptus.