The Curious Incident of the Dog in the Night-time

Both Christopher and his father say "I love you" with their fingers (hands).

He held up his right hand and spread his fingers out in a fan. I held up my left hand and spread my fingers out in a fan and we made our fingers and thumbs touch each other. We do this because sometimes Father wants to give me a hug, but I do not like hugging people so we do this instead, and it means that he loves me.