We have the greatest pre-nuptial agreement in the world. It's called love.

The line treats “love” as a kind of moral contract that precedes and outclasses any legal pre-nuptial agreement. By framing affection and commitment as the “greatest” prenup, the joke implies that genuine love already contains the promises people try to secure with paperwork: mutual care, fairness, and good faith. The humor depends on the tension between romance and the pragmatic, often adversarial logic of asset-protection. It also lightly critiques a culture that expects marriage to be negotiated like a business deal, suggesting that when love is real, it functions as the strongest safeguard—though the irony leaves room for readers to note that love is also unenforceable and fragile.