Different strokes. (Ha! Ha! Ha! He said "strokes" in the same conversation about boners!)
As I said I see the word, I know what it means and the time it was being used and don't find the use funny. Again, it's just giggling at a word or even it's use in a sentence.
But, I don't find the idea of boners or their use being funny in pretty much any situation, so...
Funnier to me when a panel is taken out of context not because of the words in it and their current meaning but just that its an odd panel out of context.
(Seriously, what IS the story behind Batman's teeth marks inside a
thong?! And why
does Robin sleep in the same bed as Batman given that they
live in a mansion! Was a pre-teen boy sleeping in the same bed as an adult man
ever considered okay?!)
So. Double entendres. For or against?
Double entendres can be funny but, again, that's something a bit different than what's any these panels. They weren't made to be double entendres they were made because "boner" means a mistake and didn't mean erection when the comics were made. It was an acceptable use of the word (otherwise I'm guessing the CCA would've had a shit-fit.) Double entendres are intentionally mis-using words to be suggestive. You're
meant to read more into in order to "see the funny." Just like "That's what she said!" jokes.
This? This is Batman, Gordon, Joker, whoever using a word that means/meant "mistake." People are giggling over the word boner. It's been a while since I giggled over the use of a single word taken out of context.