The Trojan War
The Lovers: The Spartan king Menelaus, his wife Helen, and her lover Paris of Troy.
The Gesture: The most legendary war of all time. As described in Homer's Illiad, Paris and Helen fell madly in love with each other, and ran away together back to his home turf of Troy. Menelaus was understandably peeved, and cajoled his Greek allies into launching an enormous army to recover Helen and seek revenge against the Trojans for the insult. Over nine years, thousands of soldiers perished and Troy was razed to the ground, all because some flaky Spartan queen was the Achilles heel of two powerful men.