He told her:
You are the only woman I could marry.
The one woman I dream of having near me,
even and especially when she is old and wrinkled.

She told him:
Prove it.
Go years starving, having me ignoring you
and hating you.
Being lonely, frustrated, doubting your dreams, thinking this love is only in your head.
Then, spend years being surrounded by a thousand beautiful girls, distracted every moment.

And then, I will come to you,
weak, wrinkled, not glamorous anymore.
Then you will be tested: Is your heart truly mine.

He answered:
Sounds like a plan.
See you in 20/30 years.