Damsels in Distress2011

Lily:
There no logic to the algebra of love.

Fred Packenstacker:
The algebra of love? Sounds like the title of some lame book.

Lily:
It's a title but the book's not lame at all.

Fred Packenstacker:
Love's algebra? I always thought it was more geometry.

Lily:
Okay, the title's not good but the book is.

Fred Packenstacker:
What's it say?

Lily:
Well, that while we're all perverse in our preferences, there's actually this logic, or algebra to our perversity. And it has something to do with how the species has evolved

Fred Packenstacker:
The survival of the species?

Lily:
Yes, and whether it will continue to do so.