It was a conversation after a movie that made Anna Ungar realize it was time to give her daughter an erotic novel.

Her 17-year-old had just seen Call Me By Your Name, the 2018 homoerotic film set in Italy that depicts a love story between a teenager and a slightly older man. She loved the film but kept bringing up one particular scene she thought was “weird.” It was a short interaction between the two main characters in which the man sensually rubs the teenager’s foot. The scene was so funny and odd, the teen told her mother. She couldn’t understand how touching another person’s foot was supposed to be sexy.

“I thought, ‘What do you mean?’” said Ungar, a clinical research coordinator who lives in Seattle. “Of course touching a part of someone’s body would be sensual.”