The Game-Theoreticians of Candlekeep have identified two different approaches to gaming. The first approach would be a sort of emulation of J.R.R. Tolkien, a heroic or anti-heroic saga created by the players as their characters fight and spellcast their way to fame and fortune.
The second approach to gaming almost certainly has penis jokes from time to time, or at the very least a healthy dose of Monty Python and the like. I don't mean that it's written into the adventure; even the bawdiest of DMs, if they're experienced as a DM, knows that the players will create plenty of humor on their own if left unchecked. For the DM to write it into the adventure is probably going to fail. I don't know why, but it just seems too heavy handed. On the other hand, if the thief suddenly says, "*snurk* this ten foot pole is longer than the wizard's staff, so I better do the probing," that's stone-cold brilliant. Cue for everyone to fall down laughing.
Some DMs try to restrict this sort of thing, attempting to get the players to stay "in character," or stay "focused," or even "serious." I can understand that kind of play. Really, I can. I saw someone post the other day a triumphant announcement that his character had done this-and-such, slaying that-and-such, and being awarded the barony of where-and-such. The pride was glowing, and you could tell that this adventure session would be talked of forever, possibly a high point of the guy's life.
(let me tell you about how when I was 12, my character became the King of Celene in Greyhawk, if I can ever corner you at a convention some time.)
So, that sort of epic in-character gaming can be rewarding beyond belief, I totally get that. But then ... there is penis-joke gaming. And penis-joke gaming is always awesome, because it's a game. It doesn't forget that it's a game. And, you know, even if you name your stronghold something like "Bigspire of [Character Name]," the World of Greyhawk can absorb that kind of humor. Heck, the place was built on puns and anagrams in the first place.
So, even if it's not ACTUALLY penises that arise from the group's humor, having a good mix of at least potential humor -- without being "serious about the fantasy" -- makes for more fun in the long run, in my opinion. And even if the DM is making everyone speak in Tolkien's Quenya dialect of Elven ... the DM will probably discover that you can make penis jokes in Quenya, too.
Welcome to Candlekeep. *Snurk*