While he was at the island with Kirke, she had taken him as a mate.  While he was on the island, he had three children with Kirke the youngest being Telegonus.  When Telegonus grew up, Kirke sent him to find Odysseus, who by this time had finally returned to Ithaka from the Trojan War. On his arrival Telegonus began plundering the island, thinking it was Korkyra (Corfu). Odysseus and his oldest son, Telemakhus, defended their city and Telegonus accidentally killed his father with the spine of a stingray


Kirke & Odysseus