Conversation with D-: 'Dan' is kinda like 'Danger'

Here's another odd Conversation with D-, the first part of which took place while he was very intently reading a "First Word" book M- had left lying around:

D-: (looking up from the book) 'Book'. It's kinda like 'butt'.

Me: (confused, but encouraging his explorations into reading) Kinda, I guess... they both start with B...

D-: It's kinda like 'butt'. Like people have a butt, but it says 'book'. It's kinda like 'butt'.

Overall, he accomplished what I believe was his goal of saying the word "butt" at least 15 times in under a minute. The strange part is, this isn't some kind of restricted-use word when we're all just hanging out at the house (I'm assuming that discouraging him from shouting out "butt!" at the top of his lungs in public counts as a restriction), but apparently it was giving him a perverse thrill, like when he finds an excuse to use our real names.

"...Like when Momma calls you 'Dan' sometimes? I'm not calling you 'Dan', I'm just saying that Momma calls you 'Dan' sometimes, cause that's your name-- 'Dan'. But only grownups can call you 'Dan'... kids can't call you 'Dan'."

If you think I've taken liberties with reality, and that isn't a direct quote, well, you don't know Dan's son.