This is SUCH juvenile humour, but I just about drowned laughing anyways.... I was ocean diving with a close buddy (he's like having an idiot little brother with you), just after he had done his cavern course, so we were all about hand signals...
He swims frantically right up to me (facing me), and gives me the "something's wrong" hand wiggle. I look at him, and he is pointing his finger straight at me - like a kid pretending they have a gun - which I immediately understand, as the two of us are apparently sharing a brain.
It is the universal sign for "pull my finger".
So I pull his finger...........
We are trimmed out perfectly horizontally, and he has his octo ready, bum tilted up a bit, octo held down low, and releases some air. Which, of course, being air, follow the quickest route to the surface, which happens to be.... yup, looked like the world's biggest underwater fart.
Seriously, I almost drowned. And, of course, since we are mature adults, we now demonstrate this for others if the safety stop is a little boring...