Extremely Loud and Incredibly Close Steaminess Rating

Exactly how steamy is this story?

R

Oskar is nine, hasn't yet hit puberty, so there's no sexytime in his chapters. His grandparents on the other hand… well, like in Everything is Illuminated, Jonathan Safran Foer's other hit book, there are a lot of older people getting it on. Grandma poses nude for sculptures, both as a young woman and an old woman, and Grandpa gets more intimate with her than a Georgia O'Keeffe painting. It's pretty shocking how Grandma describes explicit sexual experiences in her letters to Oskar. Grandpa also has pretty steamy letters, but he never mails them to anyone.