What really stirred it up for me was rewatching KANGAROO JACK, which was supposed to be an adult comedy until they added more CGI kangaroo scenes and marketed it as a kids movie . . . now, ignoring that, let's assume it's still an adult comedy movie . . . it has all the stuff in it that you would expect to find in a kids movie that I previously mentioned: farting camels, poop jokes, violent slapstick that would otherwise seriously injure or maybe even kill someone in reality, a fat comic relief sidekick (well, okay, that one may be a little more universal), among other things . . . really, the only thing adult about that movie is the underlying themes of the mafia and mob hits, the sexual tension between Jerry O'Connell and Estelle Warren's characters, and language . . . that's about it. I otherwise don't see what's so "adult" about everything else I just mentioned - even without the rapping, wise-cracking kangaroo who wasn't even really the main focus of the movie anyway.
Don't get me wrong, there are some adult comedy movies out there that are genuinely funny, like a couple of my favorites: DODGEBALL and YOUNG FRANKENSTEIN, but again, a lot of the supposed "adult humor" in those movies is really just immature and childish . . . it only seems "adult" because the adult mind is able to understand the context many of the jokes and innuendos imply. I mean, DODGEBALL did something for me as a teenager that GOOD BURGER did as a kid: I was literally laughing so hard throughout the whole movie I almost never stopped. But what's the difference? DODGEBALL is an "adult" movie, and GOOD BURGER is a "kids" movie . . . but both are very, very similar in terms of quirky characters, a lot of visual and verbal humor, and tons of cartoonish slapstick.
Though, to be fair, DODGEBALL does still have its share of actual adult humor that would be inappropriate for kids, much of it sexual in nature.