When gaming groups get too comfortable

"My Elf opens up the portal above the village of the Blue-Men, walks over to it, pulls down his pants, and attempts to poop on the head of a Blue-Man."  *

That was more or less an actual quote from the table at last Saturday's game.  If it had been just a funny comment, then I wouldn't have given it much thought.  But no, this was the Player Character's sincere desire.

When first confronted with the plan-of-action, I didn't know what to think.  Creative?  Yes.  Amusing?  Sure.  Consistent with the familiar tropes of sword & sorcery?  Not so much.

Sometimes, our gaming group has a new guy, occasionally there's a female present.  This particular session had neither of those.  It was just four dudes who have been friends for awhile.

Yes, our gaming group has gotten to that point.  Of course, not every session containing just the four of us is going to get silly and immature, but there's a chance... and last Saturday night I wondered if an imaginary line had been crossed.

One of the problems is this: it's infectious.  Later that night, I was not immune to lighthearted shenanigans.  As DM, I was using the whispered voice of a creepy Styx-like gondola driver NPC.  One of the characters persisted with questions.  He was being a little over-cautious, and seemingly slowing down the game.  After wading through a number of his questions, I responded with (using the same vocal tone), "Stop being such a pussy and get in the boat."

Everyone laughed.  It was a funny line delivered in an amusing way.  Upon which, the PCs hopped onto the gondola so the adventure proper could begin.  Did my joke detract from the seriousness of the game or the intensity with which our collaborative imaginations kept the game world alive?  I don't know.  Normally, I restrain myself from such things.  That time, in lieu of the portal pooping incident, I decided not to hold back.

GMs have to weigh those decisions carefully.  How far is too far?  Is a jokey atmosphere a good thing to be encouraged?  Actively discourage with a sobering word?  Should the GM join in with the players' hooting and hollering, or is unspoken suppression of juvenile levity a necessary evil?  Do the best GMs strike some kind of balance?

If your gaming group has ever experienced a disturbing level of comfort where anything can and usually will be said during a session, then comment.  I want to read about what happened, and if it became an issue at some point.

VS

*  "Oh, shit!  Venger's fantasy game.  There goes Carcosa."  ~  Not an actual line from Space Balls.