The concerts you enjoy together,
Neighbors you annoy together,
Children you destroy together,
That keep marriage intact.

In these sardonic rhyming lines, Sondheim skewers the sentimental idea that marriage is held together by lofty ideals alone. Instead, he points to the mundane, sometimes petty, and even destructive shared experiences that can bind a couple: shared tastes (“concerts”), shared social friction (“neighbors you annoy”), and the collateral damage of family life (“children you destroy”). The humor is dark, but the underlying insight is serious: intimacy is often forged through complicity and accumulated history—good and bad—rather than through romance. The quote’s bite also reflects Sondheim’s recurring interest in ambivalence: love and partnership can be sustaining while also being selfish, messy, and morally compromised.