How did Odysseus upset Poseidon?

Odysseus angered Poseidon by blinding his son, the Cyclops Polyphemus, during his journey home from the Trojan War. After Odysseus and his men escaped from Polyphemus' cave, he revealed his identity, boasting about his cunning. This act of hubris prompted Poseidon to seek revenge, leading to numerous obstacles and delays in Odysseus' journey back to Ithaca. Consequently, Poseidon's wrath played a significant role in the hardships Odysseus faced on his voyage.