And I thought libs had no sense of humor...Tuerqas
It's a science textbook, so there's an outside chance it could have been written by a conservative. Liberal arts are a complete wash, but the sciences still have the odd conservative/libertarian in their midst.
I suppose it is not clear cut evidence of humor in any case. Libs could have put this in there as a segue chance to teach their child about sex: Mama, why do they call it the four 'Fs' when mating starts with an M? Well honey, you know that word 'fucking' we all use around you but tell is bad? All it really means is...Or you could be right about a conservative who is trying to convince children that fucking is all in the head, so they don't need to use the condom speech.. Maybe that is where the phrase, 'You are fucking with my head' came from. It is a hypothalamus thing...huh.