This is paywalled, so I can't tell how much the article calls out how gross this is, but the headline and blurb make it scads grosser:
When he was 42, Cormac McCarthy fell in love with a 16-year-old girl he met by a motel pool. Augusta Britt would go on to become one of the most significant—and secret—inspirations in literary history, giving life to many of McCarthy’s most iconic characters across his celebrated novels and...
www.vanityfair.com
eta: found an archived version; it's even worse than the headline. I can't believe I'm reading this shit in 2024.