The story goes a bit like this: She’s the youngest daughter of a starving family, he’s a prince whose kingdom is suffering from a curse. Though she doesn’t know it, her love is the only thing that can save his kingdom from ruin. It could be the plot of a children’s fairytale—or the plot of Sarah J Maas’s for-adults book series A Court of Thorns and Roses, which has been credited with starting a bookbound sexual revolution.

“Romantasy,” the literary genre that fuses fantasy stories with adult-only romance plots, is the leading book genre according to market research company Circana BookScan. It’s also growing by leaps and bounds, with 1.9 million books sold since January 1 alone. Hop on BookTok (the TikTok community dedicated to reading books) and you’ll find romance books rebranded: Words like “spicy” and chili pepper emojis are common positive reactions to a story, and there are hashtags dedicated to tropes like “friends-to-lovers” and “marriage of convenience.” It’s a pretty good glow-up for the once-maligned romance book category.

“A seed was planted for the craze about 20 years ago or so with the Twilight series,” says New York Public Library librarian Anne Royer. “Romance wasn’t the main plot in that or The Hunger Games, but these are the books millennials were raised on. It makes sense that they want a similar story but with more adult content now that they are adults.” She adds that Maas’s A Court of Thorns and Roses (ACOTAR) was the third most checked out book from the library last year.

It’s just another industry proving the common saying of “sex sells” true. But for a lot of women—especially mothers—diving into the genre is helping them reconnect with themselves and escape the everyday.

“There is so much sex in this book,” says Let Them author and mother-of-three Mel Robbins, who listened to ACOTAR as an audiobook. “You literally blush. And what’s so cool about dramatic audio is that I would have my earbuds in all day long. I would be washing dishes, but I’m not in my kitchen with my hands in my soapy water, I’m literally flying with Rhysand through the skies of Prythian.”