Our grandkids ages 4 & 6 have terrific senses of humor. They love Amelia Bedelia for instance. Since the 4 yr old especially finds butts etc hilarious I thought they'd love this. Neither of them thought this was funny. The 4 yr old announced after page 1 that "this doesn't make sense, everyone knows there's a crack there!" There was a smile about the idea of using a bumper only after I explained the word "bum." They both thought pages were missing at the end. I did too. Neither has been interested in reading it again and I don't think I can donate it because I'm sure some will find it offensive.