Not a novel, there was a movie called "Her" around 10 years ago. The man fell in love with a Chatbot. iirc He also used the Chatbot to do some writing.
Scarlett Johansson was the voice for Her. Can you imagine if the guy had seen her aesthetics as the personification of the AI? He would have fell in love even faster :) Nice movie, btw.
That’s what I walked away with ;)