Crystal Harris was only 21 when she entered the Playboy mansion for the first time. Within a few days, the college student moved in. She later married Hugh Hefner, and stayed by his side until his death in 2017. In her new memoir, Only Say Good Things, Hefner looks back on the paradox of sexual freedom and strict rules she lived by at the mansion. She tells NPR's Michel Martin how her perspective on love, liberation and control has changed since she left. To listen to Book of the Day sponsor-free and support NPR's book coverage, sign up for Book of the Day+ at plus.npr.org/bookoftheday