This is an expanded TED book based on Fry's original TED talk: www.ted.com/talks/hannah_fry_the_mathematics_of_love?language=en
Fry looks at the mathematics behind everything from meeting people in bars to the algorithms dating sites use to what age to settle down to wedding planning, predicting divorce, and why maintaining a long-term relationship is actually the same mathematically as the Prisoner's Dilemma (and why the same game strategies work). Short but interesting.