The First Order Condition of My Love 
(obtained from a friend, good to share, and more importantly according to one of my colleagues, “Economist should not let their love be economical”)

My utility is maximized,
When I look into your eyes.
From the fire that within me burns,
I get increasing marginal returns.

The Payoff to this game is sure,
From now on, my strategy is pure:
To be with you is my sweet fate,
I’ve no incentive to deviate.

To be together for all time, Pareto efficiency sublime.
If you would spend your life with me,
A self-enforcing contract it would be.

Arm in arm we two do stand,
I supply what you demand.

(NARITH)